SL keeps crashing horribly

When I'm in SL everything seems to work just fine until I get a random crash. It crashes into a ribbon/rainbow of colors across the entire screen and I have to do a manual restart.

I do not believe this is an overheating issue, by the way. I have switched to the Omega Drivers (like people have recommended here) and turned down the graphics setting (or at least some of the settings... I'm not entirely sure about how to reset things other then the slide bars) and none of this has made any difference. Actually it seems to have gotten worse and I can't be online for more than a few minutes before crashing.

My specs:
Intel Pentium D 805 2.66ghz (dual core processor)
Radeon ATI x800GTO 512mb PCI-E
320GB SATA harddrive
Intel D945PSN motherboard
1GB 533mhz DDR2 RAM

I'm open to try anything other than buying new parts because my computer works great with all my other games and it's really new anyway. I am planning on buying more RAM when I have some extra money but that's all.

Anyone have similar problems they have solved or just similar problems? Anyone have anything at all that might help???

Preference / adv.graphics / Enable VBO <disable that

I already did that awhile ago but thanks. This is the other info about how most other things are set and how they've been for a while:

Vertex shapes and bumpmapping and shiny are disabled.
Sun and moon are only enabled
Avatar Rendering is normal
Terrain Detail is low

The slide bars are as low as possible on the mesh details.

Almost sounds like you have a conflict in your drivers... When you Installed the Omega drivers, did you uninstall the other drivers first? Uninstalling drivers is touch and go, because even if you uninstall them, there are still bits of it scattered through your OS.. My suggestion, uninstall all grafix drivers, find a free registry cleaner and run it.. defrag your hard drive, then reinstall drivers, and see if that helps.

I hope that helps