low fps in wow, dont know why?

Hello all,

Im sure that im not the only one having this problem, but im getting super low fps in wow now, and a year ago i was getting about 20-30 more. I was in a raid alst night and my fps went down to 4fps...which sucks. I recently tried to switch my old video card, Geforce EN6800 Ultra for a Radeon HD3870 and there was no change at all. (I made sure that when i switched cards, that i used a driver clearner to remove all the old nvidea drivers and that i had the latest drivers from ATI)

I mean at some points in the game i get like 30-40dps, but its raids and such its super low. I have no idea why this is occuring, because a year ago, i was getting at least 40fps constant. Ill list my computer spec, and maybe someone can help me out. I have all my setting in wow turned down, and my video card setting set to best performace.

Operating System: Windows XP Home Edition (5.1, Build 2600) Service Pack 2 (2600.xpsp_sp2_gdr.070227-2254)
BIOS: BIOS Date: 11/01/05 07:59:32 Ver: 08.00.1
Processor: Intel(R) Pentium(R) 4 CPU 3.40GHz (2 CPUs)
Memory: 3072MB RAM
Page File: 631MB used, 4329MB available
Sound Device:Realtek HD Audio output
Motherboard: ASUS P5LD2
Video Card: GeForce EN6800 Ultra

Tonight i will try to revert to older nvidea drivers, because ive heard that that may make a difference, but any suggestions would help.

Thanks
Troy