I checked out the link you provided but the site only covers latest 1066MHz and 1333MHz devices and the motherboard certainly supports 800/667 and 533MHz DDR2
Simple system setup, is as follows
PSU 300W
Samsung SP160N SATA drive
TSSTcorp CD/DVDW TS-H653l SCSI
AMD Athlon 64 x2 5600+ at 2.8GHz
Windows 7 32 bit OS
The motherboard is Rev 2.3 and I have the latest BIOS rev FC.
Using both on board graphics and sound
Currently running with only one 2GB strip of RAM fitted to DDR2_1