OK, I ran the Western Digital Diagnostics, and it passed the quick test, but stalled the computer on the extended test at about 4 - 5 minutes with a BSOD message that the process was stopped in order to prevent damage to the computer. I got the same BSOD when performing some Acronis TI imaging from within Windows. I expect this is the result of cloning the 40 GB drive to the WD 250 SATA. BTW, the 40 GB IDE drive boots without any problem, hence the issue seems to lie with the SATA drive. There are no problems when using the TI rescue CD, it performs imaging and cloning functions, but haven't tried a restore.

I have submitted tech support requests to both ASUS and Western Digital and am awaiting responses. If I receive a correction to the boot up problem I intend to reformat the HD and start over.