Help!
 

Please, refer to the following post for my problem:

[URL]http://forums.guru3d.com/showthread.php?p=2591615#post2591615[/URL]

I just did a 51 minute torture test using Prime95. No errors, no warnings.

Am I safe?

The Prime95 torture test doesn´t really put any stress on the HDD, it basically stresses the CPU, chipset, and memory subsystems.
Given the situation you described, I also tend to agree that something is wrong at board level, and that the disk should be OK. Is it a SATA or SATA II HDD? The MB you have has SATA II interfaces, and although it should be in principle compatible with a SATA I drive, you might at least check whether it is any compatibility issue, like some setting at BIOS level.
You could also try to plug the HD into a different SATA socket of the MB, just in case there´s something wrong with the physical interface.

I would change the SATA cable + SATA connector to which you are connecting HDD.

re-seat sata connections
run seatools google it
run memtest 86
check stupid things like all the power plugs