I have been getting lag in certain dungeons, whetehre ive been there before, or they are new dungeons , it seems random and when stuff, like fighting or what not is going on. An xbox reset fixes it, but it happens and this never happened in vanilla. Anyone else having the issue?

After 1.6 I have noticed problems with lag.

I have the exact same problem, after playing for awhile I start to get extreme lag. And I just go to Xbox Home to get rid of it but it keeps coming back.

yeah it's like your hard drive needs to be streamlined or something. it juts worse than it did before and it was bad enough before now it REALLY stutters often.

Try:
Clearing the cash and installing to hard drive. Also if you have allot of saves ( over 400 in total- im lazy) like me then it seems to cause lag when loading cells.