screen size wrong while using kvm switch

[Mike P.]

Screen size wrong while using KVM switch in 8.04.
Used same hardware with 7.10 with no problems.
Sees nvidia card correctly and lists plug and play Westinghouse 19" monitor at the correct resolution of 1400 x 900, but the desktop is much bigger than the actual screen. Works correctly connecting monitor directly to the box.
Mandriva doesn't have this problem, so it seems like a Kubuntu issue.
Doesn't matter if I use nvidia's driver or not.
Also works correctly using the KVM switch when booted from the live cd.

Any clues?

Thanks,
Mike P.