The computer was booting with one and not the other?
You can check
www.crucial.com or
www.intel.com for information about that board's memory capabilities.
If I remember right from the two I have of that model:
DDR266 if system bus is 800MHz, 533MHz, or 400MHz
DDR333 if system bus is 800MHz or 533MHz (gets underclocked to 320MHz)
DDR400 if system bus is 800MHz
The memory information for that board can be found
HEREI just verified the information about speeds there. Surprised I can still remember that, I've had these boards for years. Anyway, check that page for more complete information and check your bus speed.