Well...
First... there are many many many posts on this subject, so I'm not sure why you couldn't find any. There's a FAQ on it here, too...
http://www.wowinterface.com/forums/s...ad.php?t=21716
However, that being said, I would hasten to add that the average human eye can't see a frame rate faster than 24fps... so until you get into combat, I'm not sure the frame rate matters if you're seeing 30+ -- obviously, the 10fps in combat is an issue.
The instructions in the FAQ above may help. However, it is known that there is an FPS leak in the aura displays for nUI5 which is a large part of why the re-write for nUI6. I might suggest you try the nUI6 Alpha and see if it helps your frame rates, as well.