I registered just to show you this video I made.
I tested this reason several times with the same results.

http://www.youtube.com/watch?v=CGAWA1YeR7Y

It only happens when a dragon is STUCK. You will have no sighn of an enemy on your compass, nor will you hear that a dragon is there.
I hope this is of any help, maybe...
Sorry if my English is strange.

About my game status:
My Save File is 15MB, was 16MB pre last Patch.
I had heavy FPS drops before the last Patch and it is much better post Patch.

Wow...Send this to Gstaff right now!

http://www.gamesas.com/index.php?/user/365941-gstaff/

That may be part of the issue, or they may be stuck because the game is chugging. People were reporting the fps thing long before dragons went crazy though so I'm doubtful if it's the primary cause behind the fps issue. They also get fps chaos indoors when there's no dragon in existence at all.

Very interesting observation, thanks for making this video!

That is a really good observation.

Kudos to you for registering on here to post that video!

I don't know why it happens indoors

But I see this as ONE reason.

I saw the dragon flying like crazy, everything was OK with FPS. I followed it all over the place, it got stuck and was very high and immediately the stutter started. Shot arrow and everything fine again.
Several tests like that.

Edit: BTW I have this Dragon as a quest targed, that is how I could follow it.

I'm going to fire up my game now and give this a try. When you had lag, if you teleported away, would it still lag? Or would it be cleared?

Sadly not tested, but good idea!

Oh wow, that's a big find. Your frame rate cleared RIGHT up.

On my game the patch seemed to have fixed the lag quite a bit. I'm not high enough level yet to really compare, but I was running a 12-13 mb save with 80-90 hours when the patch came out, and I tested it for a day. I ran my system for 5 hours (before the patch I would notice a significant FPS drop after 45 minutes to an hour) with the game on and experienced only minimal loss of frame rate before I deleted the character (I was worried about those corrupt files carrying over and wanted to start over anyway).

It's also interesting to note that the only issue I have ever had with a dragon (yet...) was what appeared to be a failed load of a normal map. I fought a "basic geometry" dragon with a smooth shader and bump map (or that's how it appeared to me) but it was lacking in the larger scales, teeth, and eyes, until it died and looked normal. I wish I got a better look at it, but it kind of snuck up on me and freaked me out.

But either way, I experienced a lot less lag, and my dragon issues are pretty small. I'm not knowledgeable to truly speculate that the two are that closely related, but I'm sure there are some who can.

I'm not sure if this problem even is about the dragons. Maybe it is the water currents +animations. When I dismount my horse, the problem with going down the river while rearing my horse is gone.
When I shoot the dragon, it reacts with a new animation and that frees it.

The horse dooing this is very rare. I had that two times pre and post last Patch and I was so clever to film it^^

I can't seem to find any spazzing dragons, only ones that are flying normally (not even backwards). Crap D:

I can also confirm (as I posted in another thread) that my lag seems to be much worse when a dragon is flopping around stuck in a tree or mid-air also. As soon as the dragon warps away, it generally gets less laggy. As soon as another tard dragon appears, lag ensues again. I tried to take a vid, but couldn't get it. Would it be useful if I got another vid?

Sorry your reasons are perhaps false. Menus lag as well as everything else. Sometimes the menus don't but they do plenty of times. Lets just agree the game is bleeped up and nobody is going to ever find the true reasons as to why the game is a glitched mess besides Tom Howard or whatever his name is..

Absolutely. Every little bit helps.

Excuse me, but that seems like a statement made out of anger, rather than reason. I'm not the most tech-savvy person in the world, but I DO know that when I run a game on my PC (I have a fairly weak PC and tend to stay away from too many PC games) that when I jack my settings up too high my menus lag the same as my game. It's not like you have a separate set of resources devoted to just your menus- if something is lagging up your game it will lag up all aspects of your game.

Am I right?

I'm just sad.... And annoyed... And I just wanna kill the damn dragons in peace!!!! And Lydia.... Oh my sweet Lydia!!!! Why are you always getting lost!!!!! I fear she shall not return to my house in Whiterun this time for she is..... Dead Jim..

Wow what a helpful video, good job!
This might also explain why I haven't had any problems at all, I am avoiding the main quest all together and have not yet spawned the dragons.

Could you provide more information? How many hours have you played, what level are you on, and how big is your save file? How many locations have you discovered?

I think it's a good idea to test a large portion of the game dragon-free. If you're already doing it please keep us updated.

It's funny that people always say being a play tester would svck because you always just play broken games. It's still fun, to an extent.

LOL!

You know whats an interesting coincidence? I also played a big part of the game without spawning the dragons. I have now for a week or so. But I played for almost a week or more without doing the third main quest and spawning dragons.. I wonder if that is part of the reason Im not seeing any issues yet?

We need to test this in someway, but the only way I can think of is this: If someone could do a new character doing nothing but dungeon raiding, throwing stuff about, side quests, and killing NPCs, but not touching the Main Quest at all. Then see if their performance is affected. This would keep dragons from spawning, and if they are, or are a big part, of the problem. It would be eliminated.

Well I just had an experience with the strange dragons. It was the dragon bounty in the middle of the march in the Riften area, if that helps at all.

It tried to stay the same distance from me at all times. When I moved forward it moved backward (well, away from me, it had no real coherent "direction"). Sometimes it would free itself, and you could see that the animations were very off, as is often reported. He was banking in all directions while flying straight, and often flying back-end when he was free from whatever kept him at a distance from me. The thing that really svcks is you can't fast travel while they're after you and you can't hit them. Eventually I was able to get him stuck into a mountain that he couldn't get out of and just booked it, did a quick fast travel, and gave myself a pat on the back.

During this time I noticed an extreme drop in the frame rate (actually looked just like Zidane Tribal's videos). This drop continued, even after I no longer saw the dragon. Not too long after the encounter (I was about to give up because the frame rate didn't improve much after this encounter) my system locked up. When I restarted it I was informed that the system didn't shut down properly and went through that whole dealio.

So, after I loaded the dragon and managed my escape my frame rate never went back to what it was before the encounter. I don't have any meter devices to record specifics, so I can only be general and say that.

Luckily I had all of my auto saves off, so I never had a save after this encounter. I loaded it up again and went after the same dragon... out of curiosity, if nothing else.

The dragon was exhibiting the same behavior, and then my frame rate went right down again. It's interesting (though I don't know if helpful) to note that there was another dragon in the distance that appeared to be acting normally. I say appeared to be, because really only 1/4 of the dragons will fight me anymore.

Anyway, this time I shut off the console before it locked on me and have decided to put this down until the next patch. If nothing else this forced hiatus from Skyrim is good for my productivity.

Save file seems to have "capped" at around 5500 kb, level 21, 20-23 hours gameplay. I have discovered Winhelm and a few smaller outdoor areas, but my save file is now staying around there, and seems to go down when it reaches 5500, even after discovering new locations. Don't know if it's a coincidence or not.

Please note that I don't think this is a huge part of the problem or anything. At this point I'm just "reporting" something that happened shortly after, while it's still fresh and I can remember a few details.

It has nothing to do with the main quest. After the patch I have completed the whole quest and never got a single bit of lag. I also see dragons all the time and never encountered a bugged one. I've been doing tons of side quest now since I have finished the main, and still have not been hit with any lag.