2008 pro, 8800 card, freezes, Timeout

On occasion I've been having my Graphic card freeze and time out. Usually whenever I'm on Firefox. Either one or the other is causing the problems, but I can't figure it out. Hopefully it's a software script thing. and am on 2008 Mac pro, running 10.5.6 12 gb ram.

4/16/09 1:02:39 PM [0x0-0x1a01a].org.mozilla.firefox[253] Debugger() was called!
4/16/09 1:02:51 PM [0x0-0x1a01a].org.mozilla.firefox[253] Debugger() was called!
4/16/09 1:03:13 PM [0x0-0x1a01a].org.mozilla.firefox[253] Debugger() was called!
4/16/09 1:03:38 PM [0x0-0x1a01a].org.mozilla.firefox[253] Debugger() was called!
4/16/09 1:03:48 PM [0x0-0x1a01a].org.mozilla.firefox[253] Debugger() was called!
4/16/09 1:03:54 PM [0x0-0x1a01a].org.mozilla.firefox[253] Debugger() was called!
4/16/09 1:04:01 PM [0x0-0x1a01a].org.mozilla.firefox[253] Debugger() was called!
4/16/09 1:04:02 PM [0x0-0x1a01a].org.mozilla.firefox[253] Debugger() was called!
4/16/09 1:04:02 PM [0x0-0x1a01a].org.mozilla.firefox[253] Debugger() was called!
4/16/09 1:04:50 PM kernel NVDA(OpenGL): Channel exception! status = 0xffff info32 = 0xd = GR: SW Notify Error
4/16/09 1:04:50 PM kernel 0000000c
4/16/09 1:04:50 PM kernel 00200000 00005039 00000474 00000000
4/16/09 1:04:50 PM kernel 0000047c 00000100 00000000 00000003
4/16/09 1:04:50 PM kernel 00000000 00000000 00000043
4/16/09 1:05:02 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:05:14 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:05:26 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:04:17 PM [0x0-0x1a01a].org.mozilla.firefox[253] Debugger() was called!
4/16/09 1:04:23 PM [0x0-0x1a01a].org.mozilla.firefox[253] Debugger() was called!
4/16/09 1:04:29 PM [0x0-0x1a01a].org.mozilla.firefox[253] Debugger() was called!
4/16/09 1:04:43 PM [0x0-0x1a01a].org.mozilla.firefox[253] Debugger() was called!
4/16/09 1:05:38 PM kernel NVChannel(OpenGL): Graphics channel timeout!
4/16/09 1:05:50 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:06:02 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:06:14 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:06:26 PM kernel NVChannel(OpenGL): Graphics channel timeout!
4/16/09 1:06:38 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:06:38 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:06:38 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:07:12 PM kernel NVDA(OpenGL): Channel exception! status = 0xffff info32 = 0xd = GR: SW Notify Error
4/16/09 1:07:12 PM kernel 0000000c
4/16/09 1:07:12 PM kernel 00200000 00005039 00000474 00000000
4/16/09 1:07:12 PM kernel 0000047c 00000100 00000000 00000003
4/16/09 1:07:12 PM kernel 00000000 00000000 00000043
4/16/09 1:07:12 PM kernel 00000000 00000000 00000043
4/16/09 1:07:24 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:07:36 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:07:48 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:07:48 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:08:00 PM kernel NVChannel(OpenGL): Graphics channel timeout!
4/16/09 1:08:12 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:08:12 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:08:24 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:08:36 PM kernel NVChannel(Display): Graphics channel timeout!
4/16/09 1:08:48 PM kernel NVChannel(OpenGL): Graphics channel timeout!
4/16/09 1:08:48 PM kernel NVChannel(OpenGL): Graphics channel timeout!
4/16/09 1:09:00 PM kernel NVChannel(Display): Graphics channel timeout!