The issue arose before I even considered using mods, so it is vanilla. However, I used a large address aware binary (mentioned earlier in this thread) - I'm inclined to believe that isn't what is causing these crashes but I haven't ruled it out completely.

@Inki: I'll try that pcb command as soon as I get the chance.

Thanks again to everyone testing this and providing their experiences.

I'm experiencing the exact same problem. At this point Markarth Underhalls, Embershard Mine and an area outside Riften will always cause CTDs. My save files are around 20 mb.

I agree, that the issue seems to strongly relate to revisiting cells where one has been before.

I have found, that using a combination of
- advancing in short spurts,
- saving just before a "hot spot",
- doing a "pcb" whenever there is any sign of stutter, and also when I haven't done it for a while,
I have been able to force my way through most, but not all open-air hot spots. I have found one invincible hot spot between a windmill and the bee farm junction on the Southern road going West from Riften.(*

Curiously, when I have a slight stutter and do a "pcb", the console often also shows one or more additional lines, something like:
XXXXXXXX >> 0
where XXXXXXXX may typically be a scripting reference or command. It at least gives me the feeling, that there might be loose scripting garbage floating in the memory and possibly in the save games, left there from when last visiting the cell. Also, I have mixed feelings on whether this could relate more to loading a new cell or letting go of an old one.

*) On my own saves that is, haven't tried the OP's.

P.S.
I have been trying to force passage through the Southern road from Riften, just to see if it would "stick" with the new 1.3.10 patch. Don't know yet. As an example, I forced my way from the road junction to the front door of the bee farm (and treated a couple of radiant nirnroots on the way), couldn't get in no matter what I tried, but then circled the house, and had stutter half way around, where "pcb" displayed many additional lines, and was finally able to get in through the back door. Once I had to tackle a tough spot by fast traveling to the other side and having a go from a different direction. Curiously enough, one could not even fast travel directly, but had to take a half-way stop at a clearly separate location.

Ahh this is what my problem is. But for me since 1.3 it does it with new or old saves. I even went as far as hooking up my winxp drive and it still did it with a fresh download and install of game,video, and audio drivers. Now on this i am out of my league, but with 1.3 they added some type of multiple core support? and doesn't one of the core's help with graphic's in some way's?
Before 1.3 my save file was a little over 80mb and i only crashed every 3-6hrs or so. Now it is every 1-3mins during loading of these interior or exterior cells.

One type of fairly straightforward theory could be like the one below. Note however, that a theory like this is most likely to be totally wrong, and perhaps not even in the right ballpark:

Assume that you encounter a random enemy. The game inserts into the game the actor and a script that controls it. When you kill the actor it usually remains, if there are not too many dead bodies in the cell already, and the game marks it as something to be removed when the cell is reset. All the cell content that in any way deviates from a pristinely clean cell is then flushed into a savegame when you do a save.

Assume then, that you leave the cell for 10 days or more. When you return, the game loads the relevant data from the last save, and notes that you have not been here for 10 days, and everything that has been marked as temporary, and to be deleted, should now be removed, and you should be presented with a reset cell. We already know, that this does not work well with ash piles. (Nirnroot glows may be a similar but still slightly different kind of thing.)

Now, if it were to happen, that when performing the cell reset, the game removes the dead enemy actor, but fails to clear its script, we may have an interesting situation with a script, that has no valid reference, and may or may not attempt to do something that is more or less inconvenient in that situation. Note, that a similar thing could well also apply to any actors, that are not random and temporary, but rather a permanent fixture, that is not intended to reappear when the cell is reset, but should be permanently disabled or deleted when killed, like the guards at the bee farm.

P.S.
Following this logic, if one wishes to minimize the size of one's save file, one should first leave visited cells alone for 10 days (or 30 days, if it the cell has specifically been tagged as "Cleared"), and then stick one's nose in just long enough to register. Under those circumstances, all the myriad changes that you caused when looting the place clean will be replaced by hopefully not much more than the locations of newly spawned mobile enemy actors.

I ran into serious issues similar to those described (repeatable CTDs in certain exterior cells, frequent random unrepeatable CTDs, buildings failing to load, parts of dungeon interiors failing to load (3 times in different areas of 1 dungeon level!!), ground textures failing to load, remote activated doors (pull chain doors in dungeons for example) not activating etc.) which coincided with my save file exceeding 20Mb, around 300 hours of play with that character. I was unable to continue with the character after that point.

Right. I fear that if the game leaves loose scripting garbage lying around when attempting to do a cell reset, then it may be that no patch by Bethasda (if we ever get one), that just corrects the incomplete resetting, may ever fix already corrupted save files. It might require a third party save file cleaner. And that may be a long time coming, assuming that it is possible to develop one.

Personally, I am currently not really motivated to invest any more time in my on-going game, nor am I motivated to start a new one, until the issue has been sorted out.

Someone else posted a similar problem and some of his saves too: http://www.gamesas.com/topic/1318012-whats-wrong-with-my-save

I tried his savegame and could walk from Whiterun to Solitude. Tried again riding his horse but it died on the way so I ended up walking to Markath. However, going or riding to Riverwood causes weird issues like LOD trees up close instead of real trees, missing buildings and many CTDs.

With your save I tried riding north through Falkreath but the game crashed shortly after I left the city.
I tried again on foot and could move a lot further but noticed something strange: North of Falkreath on a on a little cliff overlooking the city is an old, ruined watchtower, Falktreath Watchtower, which you hadn't discovered yet. When walking toward that tower it disappeared, appeared again, disappeared once more. I climbed up that hill and got the discovered... message. But the tower wasn't there. I could walk on the spot where it's supposed to be but there was nothing but grass... I tried to fast travel to it which caused an instant CTD.
It seems something is damaged in your game-data.

I noticed something else though, both with your save as well as the other one: The game crashes a LOT faster when riding a horse.
In both troubled saves I could usually get a lot further on foot. And both troubled saves showed very weird graphical glitches before crashing.
I'm purposely NOT speaking of "corrupt saves" because the save files are ok; it's the data that they store that has issues. That's a difference because a corrupt save = a damaged file is lost. THIS might be fixed at a later time if Bethesda is able to find the problem....)

That the game seems more stable on foot than riding a horse might be a hint at the problem. It could be a timing issue with the streaming of additional cells. The longer you play a character the more data the game has to collect and restore for each place.
You move a lot faster on horseback so the game has less time to restore the ever growing list of items for each cell.
Could also be a timing/sync problem with different threads handling different parts of the same data.

Maybe timing is a reason why I have no problems at all yet (~150 hours, 15mb saves): I never used a horse. I explore on foot and often use fast travel when I want to go back to places I previously visited.

Whatever the problem is, I'm afraid only Bethesda can fix this. So posting troubled saves is a VERY good idea. Gives them something to test and reproduce the errors. Because - as I said before - it's very hard to fix errors if you don't have them...

Small update since the official LAA patch came out.

-pcb seems to work similarly to the idea of saving just before a crash spot, but again is suboptimal since using this method involves finding the crash barrier to begin with (and thus crashing at least once per cell transfer)
-the official LAA binary hasn't affected this

At this point it seems our next chance to try this is with a future patch. @Gstaff: I do hope my save game has found its way to the right people.

1.4 update announced. I'm eagerly waiting to try and see if it'll fix things. If it doesn't then I guess there's no hope. :/

im sure your save file contributed to the new patch in one way or another... thanx for actually applying yourself and not just flaming about like a stunt double on a movie set.

Hope you manage to recover your savegame man/ good luck

One final update: 1.4 seems to have fixed the crashing between cell issue I think.

I only played for about 30 minutes but I didn't get insta-crashes like I used to. Thanks gamesas!