Help! 2000 point drop in 3DMark Score

Hi:

I recently built a new system and tested it with 3DMark 05. My score was decent (~7800). Then, the following day, my score dropped to ~5800. No new software was installed, all programs remained the same, and all virus and spyware scans came back clean. My system is as follows:

AMD 4400+ X2
eVga 7800 GT CO
2 GB Ram (Kingston)
Abit KN8 SLI Motherboard
650 Watt Coolmax PSU
Running : Windows Media Center

Note: I tried the X2 hotfix but it didn't change the score. I've tuned off antivirus and spyware monitors - no change. Any thoughts?

My major issue is I am converting videos where frames are dropped every couple of minutes. The 3DMark tool gives me a good idea of whether the tweaks to the system are improving performance so I don't have to test with a video each time I make a change.

ADMIN: PLEASE DELETE THE DUPLICATE POSTS OF THIS MESSAGE _ I AM SORRY BUT I DO NOT KNOW HOW THIS OCCURED - I ASSURE YOU IT WAS ACCIDENTIAL