Stuttery Performance on all Viewers

Every viewer has been stuttering after loading everything up in a sim. I've been having this prob for a few months now.

For instance , say i'm working on a sim, I rotate the camera and it stutters (stops) for a brief few seconds, and then loads up the new items which weren't on screen previously. This is very annoying if you're constantly changing camera views or moving your av in different directions. Overall, performance is stuttering as hell, and I've never had this problem before. So I pin the blame on SL! Just because I can...


Please....no mention of updating any drivers, I will explode (and yes all are updated anyway).


Specs.

AMD 4200 dual core
2gb ddr 3200 ram
Radeon x800xl 256mb AGP Graphics Card (with Latest omega drivers)
650 PSU
Windows Xp Home SP2

Also, if I try and put up with the horrid performance, it just degrades and degrades until there's a full blown crash.

What on earth is going on?