This week, I installed 1.6.1 onto a Compaq desktop that previously
had Windows 2000 installed.

When I rebooted after the installation, the Compaq said "Invalid 
partition table". I booted off of floppies and tried to rewrite the 
partition table and MBR with fdisk, but this did not fix the situation.

What did fix the situation was dd'ing /dev/zero over the MBR. (I then
reinstalled NetBSD for good measure.)

Perhaps I missed something that day, but it looks like we don't always
write the partition table correctly with our installer.

Regards,
-- 
Chris