Memory Issues on Chaintech S1689 MB

I just purchased 4 gb of PNY DDR PC3200 400Mhz Dual Channel Ram for my
motherboard, to replace the 2gb of Corsair Ram I had.

First off, if I install all 4 sticks, it only sees 3 on the boot up. It lists the 3gb as Dual Channel.

Second, it gets as far as the Windows XP screen before the desktop
launches, and does not boot any farther. Reading up on the motherboard
at various memory sites, it states this board can handle 4gb of Dual
Channel memory. The PNY that I bought for it is supposed to work in it.

If I remove 1 stick of memory, it boots up to the desktop and sees the 3
gb and lists it as Single Channel.

Is there anything I can do to make it see all 4gb as Dual Channel and
boot completely to the desktop?

I've tried swapping to other slots. Is there a setting somewhere in the Bios that I'm missing?

Please let me know if anyone has an answer. I tried to find a support page for Chaintech, but it seems as if they no longer have one.

Might help to note a few specs:

Running Windows Media Center 2005 SP3.

The motherboard is my Chaintech S1689. AMD 64 4800 Dual Core processor. It originally had 2 gigs of Corsair PC3200 400 CL2 DDR ram installed.

did u reset ur bios before installing the new ram?