I've recently started experiencing these BSOD's even when the PC is idle. Here is the Who Crashed analysis :
On Fri 07/05/2010 10:17:15 your computer crashed
This was likely caused by the following module: hardware
Bugcheck code: 0x124 (0x0, 0xFFFFFA80076E1028, 0xFE200040, 0x60114A)
Dump file: C:\Windows\Minidump\050710-91213-01.dmp
and minidump file attached.
Thanks for any assistance anyone may be able to offer to resolve this.