Well you can use this RAM.. You'll need a S939 Micro ATX mobo though. I don't know which ones are good but here's a list of all the ones that you can use (from Newegg): Newegg.com - Buy Computer Parts, PC Components, Laptop Computers, Digital Cameras and more!
Couple that with a S939 X2 3800+.
Either that, or sell the RAM and get an AM2 system with a 3600 brisbane and decent RAM. $65(3600+) +$70(Biostar TForce550) + $130(G.Skill 2GB NQ DDR2-800). Plus, you'd actually be able to overclock it since you wouldn't be limited to MATX boards. Why didn't he just RMA it though?