Are there places you used to go to, forts and dungeons in particular, that simply do not reset anymore?

And the tower that is northeast from Whiterun, http://www.uesp.net/wiki/Skyrim:Valtheim_Towers
Do the bandits still spawn there?

I'm trying to see if I've encountered what I like to think is a major reset bug..

Valtheim Towers still respawns for me. I use it for Bandit Thralls. I'm on PS3 by the way.

If this isn't happening on consoles(a good thing), this may be another isolated problem I'm having.. but I need to make sure.

I don't get taken seriously when it comes to bug reports, so I don't bother posting my finds in the USKP thread.

Yes, a few, but I haven't really checked it yet. I know for sure Valtheim Towers and Helgen aren't respawning for me anymore. I believe the ancient Nord tomb next to Ivarstead (behind the inn) has no enemies anymore either.

Fort Kastav has not reset with its Mage nasties for many game moons. I do go past with serious respect each time I have to get to College of Winterhold, but miss the intense mana fights

A few have, a few haven't. I do remember reading something about enemies resetting every 10 or 30 days, so maybe that expains why some reset and some don't?

I have a new character, but my last was level 72 with no fast travel. The towers listed above NEVER respawned and I killed everyone really early.

Also most 'hostile' animals very very rarely respawned, and horkers never did. Really weird. Now I did go on a soul trapping mission mid game to raise enchant, and soul trapped every horker on the northern coast so maybe soul trapping prevents them from coming back.

Kastav is one of the forts in the game that appear to become populated by Imperials or Stormcloaks after you clear them, even if you have not chosen a CW side.

Last character Bthalft stopped respawning for me which was annoying because I had a quest to kill a bandit leader there.
I think the problem arises when you revisit a cell before the respawn period has elapsed. Obviously outdoor cells are much more likely to have this occur than interior cells.

Going somewhere and waiting it out doesn't reset these areas anymore, either. I'm willing to believe the forts will not reset if they are the ones to be occupied by the factions regardless if you start the Civil War quest. Fort Greymoor being an example. That place has been empty for a good 2 months.

Most areas that are marked "Cleared" reset after 30 days of you not entering the cell. Most areas that are unmarked reset after 10 days.

I believe there is a bug where if you entered area between 2 and 9 days after clearing, it would never respawn again. That may be the case with you and Valthiem. Valthiem can be a heavily trafficked area in the beginning of the game, especially if you do not fast travel.

Reference: http://www.uesp.net/wiki/Skyrim_talk:Respawning (The original source of that information is somewhere in this forum. But somehow I'm never lucky searching this forum.)

Oh crap -.-(and I'm on the PC, and my respawn timers where changed to 3 days).

And it isn't ust Valthiem. I mentioned it since it was likely everyone's first tower they ran across(like Vilverin was the first Ayleid ruin for most of us in Oblivion).

So I wasn't crazy thinking my game was slowly but surely becoming unpopulated FOREVER.

Yep unfortunately there's a bug that causes this if you go back to an area too soon after you clear it for the first time. My first character fast traveled a lot and this never happened. My next two characters never fast traveled and pretty soon nothing would reset since I was walking back and forth past places I had cleared doing quests that make you walk back and forth. Yea. So those games are pretty much screwed for respawning.

Uh-oh. Guess I'd better keep that in mind then. Good thing my present character is quite a pacifist, so most animals and dragons are still roaming the world. But I'm fearing for the draugrs and bandits.

On the other hand, that mine at Shor's stone got repopulated by spiders again, and that's about the only one which shouldn't. I don't want the villagers to die. Maybe I'll try this bug out on it, so it'll stay clear.

The Dwemer ruins don't seem to reset. They're bone dry, I've completely cleaned them out. This included Blackreach.

They respawn for me,Wish i could kill all enemies of a place then take over the fort or something

I think that's stupidly intended. However a good majority of them are quest related. What you'll notice is when quest related areas are cleaned out, they never reset. This pretty much means nearly all of the nordic ruins. I don't know why they set it up this way..

Anyway, thanks for all the replies. I'll have to be more careful with the remaining areas of my game lol.