KN8 SLI Memory Problem

I've just purchased an Abit KN8 SLI motherboard for use with some of
my old components to build a second system. These include an AMD
Athlon 64 3500 CPU and 1 Gb Corsair PC3200 RAM (2x 512Mb matching
pairs).

I inserted the RAM into DIMM slots 1 and 2. The system POSTs fine and
the memory is running in dual channel mode and command rate 1T.
However, the system cannot boot from any Windows CDs. All the media I
have are original CDs or DVDs and it fails with similar errors with:
Windows XP SP2 CD, Windows 2000 Professional CD and Windows Vista
32bit DVD.

I checked the memory with WinDiag (Windows Memory Diagnostic tool) and
sometimes it passes all tests fine but one occasion it failed two.
However, I tested the memory in another system and it works fine. I
also tried another Corsair PC3200 matched pair taken from a working
system and it gives exactly the same error. I then put the original
memory sticks in Slots 3 and 4. Now everything is fine. Windows
installs without any errors at all. Everything is stable - I ran
Prime95 torture test for 2 hours without any errors.

I just wondering if there is a fault with my board i.e. DIMM slots 1
and 2 which may cause problems later on.

I look forward to hearing from you and many thanks for your help.