I replaced a ps/2 mouse with an usb mouse and then my system wouldn't boot.
I use lilo and it gave a '99' error over and over. Booted the gentoo install
CD, mounted my partitions and chrooted then rebuilt and reinstalled my
kernel. Reran 'dolilo'.

Still no joy. I had made sure I didn't have a camera card in my hp 8200
and that any other unusual usb devices were disconnected. Then I thought
about the mouse and removed it and reinstalled the old one. Then the
system was able to boot!

How the hell can a usb mouse prevent booting? Does it confuse usb-storage
and create a block device that slides in to replace /dev/sda? I was able to
boot the cdrom, but not the hard drive.