Asus A7V400-MX motherboard memory problem

Hello,

Since a few days I have a second-hand motherboard (Asus A7V400-MX) with
a default memory dimm of 256MB (DDR PC2700 256MB). Because I want to run
SuSE Linux 10.3 on it to manage my synthesizers, I had to extend the
memory with a dimm of at least 1 GB. My vendor gave me Kingston
KVR400X64C3A, which I had installed at once. After booting up, the
computer signal a long beep, what means that the memory was not
installed or detected. Is it possible that the memory does not suite the
main board? The manual of the A7V400-MX mentioned the memory module as
applyable, so what could be possibly went wrong?

Kind regards,

Johan.