Hi,
I believe that the culprit is faulty motherboard as one of the minidump has CPU_CALL_ERROR and POSSIBLE_INVALID_CONTROL_TRANSFER. Replace the motherboard will fix the blue screen problem.
Mini012806-01.dmp
BugCheck 100000D1, {6d6dd0, 1c, 8, 6d6dd0}
Probably caused by : hardware
STACK_COMMAND: kb
FOLLOWUP_NAME: MachineOwner
MODULE_NAME: hardware
IMAGE_NAME: hardware
DEBUG_FLR_IMAGE_TIMESTAMP: 0
BUCKET_ID: CPU_CALL_ERROR