Just built a system using an Asus M2N68-AM Socket AM2+ Motherboard, AMD Athlon 64 X2 processor, 1GB of Kingston KHX8500D1/1G and 3 Western Digital WD10EACS 1TB drives.  Everything appears to be working fine.

 

Only small note is the Bios configuration to boot to the USB device.  You have to go into the Hard Drive Device settings and set the USB Drive to be at the top of the boot order for the drives.  Then, go into the boot order screen and tell it to boot to the USB drive over CD-ROM and Floppy.

 

If you don't put the USB Drive at the top of the HD list, it won't be available on the boot order list.

I have added this board to the wiki here with a link back to this thread so that people can make sure to set the BIOS correctly.

Additional detail, as I added an IDE drive from my old data server and it didn't boot.  Apparently the BIOS decided to reorder what was listed under "Hard Disk Drives" and the USB device was no longer priority.  So, I wrote down the exact names.  Here's what to do:

 

After going into the BIOS, select "Boot" from the top of the screen.

 

Next, select "Hard Disk Drives" and highlight the USB Device and press the + key till it is at the top.

 

Next, press ESC to go back to the "Boot" screen and select "Boot Device Priority".

 

Again, highlight the USB Device and press the + key till it is at the top of the list.

 

You should be all set at that point, but again, if you make any hardware changes, be prepared to check the BIOS settings again, and put the USB device back at the top of the "Hard Disk Drives" list.