I got the patch for DG in germany today.
But that made my overall game experience much bader! The games laggs, it freezes old quests are bugged!
WTF?!
I never experienced LAGG before dawnguard and freezes didn't happen that often!

I don't notice something like this on my version... sorrry

Same prob here. Never had any issues with lags or freezes, but with dawnguard + Patch it constantly (about once per hour) freezes in loading screens or ingame, and it lags (especially right before finishing move animations start) regularly.

And what about clearing the cache before starting dawnguard ? You've skyrim installed on hard disk ? What model of 360 do you have ?

All these informations would help to find a possible solution

Cache has been cleared before starting skyrim, it's installed on hd and it's the new, smaller Box. Can't tell exact Version now as i'm not home.

have you already tried to disinstall it from hdd and play straight from disc ?

Gonna try this tonight thx.

I've never had this issue, I've had lag before DG was released, but after it's been fine. If you're having lag then save, and restart the game and it should be fixed. I;ve only ever had one crash and that was last night on a loading screen, but that's it.

I've never had to clear the cache.

Clearing the Xbox cache can definitely help. You can also try deleting Dawnguard and redownloading.

First of all thx for the responses. I've tried some stuff. As I clear my cache everytime before I start Skyrim, obviously it wouldn't solve my lag/freeze prob. Then I deinstalled Skyrim from HD and played from disc, didn't help either. On an usb stick I still had some saves which never ran with DG, so I deinstalled DG an tried those saves, no problems at all. So I re-downloaded DG an now everything's fine oO. Played for like 4 hours without any freezes and only 1-2 lags, which ofc can totallly happen. So redownloading it definetly solved the prob FOR ME.