Help with an error during RVS

Im not sure if this is the place to ask, but installed Rainbow Six 3: Raven Shield back on my computer yesterday and everything was working great until I stopped playing and tried to play again last night. When i start the game the first time i get this message:

OS: Windows XP 5.1 (Build: 2600)
CPU: GenuineIntel PentiumPro-class processor @ 2667 MHz with 1023MB RAM
Video: ATI Radeon HD 4800 Series (643)

General protection fault!

History: UGameEngine:raw <- UWindowsViewport::Repaint <- UWindowsClient::Tick <- ClientTick <- UGameEngine::Tick <- UpdateWorld <- MainLoop


And when i start it the second time I can get to the point that I load a multiplayer map and I get this error and a game crash:


OS: Windows XP 5.1 (Build: 2600)
CPU: GenuineIntel PentiumPro-class processor @ 2667 MHz with 1023MB RAM
Video: ATI Radeon HD 4800 Series (643)

Failed changing screen resolution.

History: RecreateDevice <- UD3DRenderDevice::Lock <- UViewport::Lock <- UWindowsViewport::Lock <- UGameEngine:raw <- UWindowsViewport::Repaint <- UWindowsClient::Tick <- ClientTick <- UGameEngine::Tick <- UpdateWorld <- MainLoop

I have it running in Windows XP mode, even though I have Vista 64bit. I cant find and answer to this problem anywhere and have searched all day.

I am running windows 64 bit, radeon 4870, 4gb ram, quad core intel cpu. Just wanted to see if anyone knew the causes to this so I could play some of my old favorites again. If not i guess im just screwed. Thanks for any help in advance. Oh im running the game in 1680+1520 i believe??