I have been suffering from FPS drops lately really bad, going from an average of over 120 fps to 30 and locking at 30 until I zone or just wait it out.

I figured out it was "Limit frame rate when client is inactive" I had unchecked that and that's when the problems started. I checked it again and I stopped getting frame rate issues. Uncheck it, problems start again, check it and they stop.

So some of the frame rate issues that have been persisting for people since 3.5ish may be behind that?