Hard Disk Drive not Recognized as Startup Disk

Hi:

I am an experienced Mac user, and have been for 20+ years. But I need a little help.

I recently purchased a Western Digital 'Caviar Green" SATA internal 3.5" disk drive (model number WD15EARS-00Z5B1). I installed it into my Mac Pro as I have done with several other drives in the past.

After installing it I loaded Snow Leopard and attempted to make it my startup disk. However, my Mac Pro will not recognize it as a startup disk. I wrote to Western Digital to ask if they had a firmware update to fix this issue, and they responded with this:

"Thank you for contacting Western Digital Customer Service and Support. My name is John E.

It is possible that the drive may not be compatible with your computer. Western Digital does not have hardware compatibility information. You may need to contact Apple to see if this drive is on their Hardware Compatibility List (HCL).

Sincerely,
John E.
Western Digital Service and Support"

The reason for this post is that I find it hard to believe that a supposedly industry-standard SATA drive would not be supported by Mac OS X. My current feeling is that the drive is faulty, but Western Digital is pointing the finger at Apple.

Any help re: this problem would be appreciated. Oh, and before I contacted WD about this, I ran disk utility and disk permissions repair on the new WD disk drive, and I reset my Mac system's PRAM. Is there something else that I could try?

Thanks,

-AstraPoint