Since 3.3.5 patch, every 5 mins or so and for 30 sec aprox. my fps rate drops down to 5, and then they restore back to normal rate (40-60). This seems to be happening anywhere and anytime in the game. I've been enabling and disabling addons to find out if any of them was causing the problem but this is happening anyways. Is there anything related to this problem I can do to solve it? It's really annoying.
I only run msn and sometimes wmplayer as background programs. Without addons seems to happen too but less frequently. And no, I haven't ever used AVR. This is weird, aint' it? :S
If you're still trying to fix this, I strongly recommend Defragmenting...any serious FPS issues of mine in the immediate aftermath of 3.3.5 vanished. From here on out, I will defrag after patching...not sure if I probably should have beforehand.
I've realized something. Sometimes when logging out from the game (and only when logging out), it suddenly gives me a critical error and the game closes. How may I know which addon is involved? I'm pretty sure it's an addon what's causing me the problems.
I've also defragmented as you mentoned it and it seems to smooth the performance of the game but still having low fps pikes.
Back up your interface and WTF folders, then run the wow repair. If you are suffering from the lag spikes / critical errors with addons disabled then I doubt it is an addon issue.
Also run your virus scanner / whatever you use for spy ware/add ware removal.