I had two of these errors, roughly 2 days apart. Both were after I had left to the PC alone and I presume it went to screen saver. I installed Windows 7 three weeks ago (fresh install) on a new hardrive and created a dual boot with Windows Vista.
The computer has rebooted from a bugcheck. The bugcheck was: 0x000000ea (0xfffffa80080dcaa0, 0x0000000000000000, 0x0000000000000000, 0x0000000000000000). A dump was saved in: C:\Windows\MEMORY.DMP. Report Id: 012610-25740-01.
As a precaution today I ran the basic diagnostics from Windows Memory Diagnostic with two passes not showing any errors and updated the video driver
for the ATI HD4850 card with the latest ATI driver. The previous driver was from windows.