Originally posted by revz
The only thing I can think of is your kernel config. You will need to make sure the proper USB support is included...some can be modules, some things work best if compiled into the kernel (like HID).
1) If you have a ps/2 keyboard lying around it would help until you get it worked out.
2) If the keyboard worked during the install, you can boot from the cd and mount your Linux partition and compile the kernel from there.
Another option would be to...
bare.i root=/dev/hdxx noinitrd ro
at the boot: prompt when booting from the CD.
Once the kernel is properly configured, then you'll need to make sure the proper modules are loading at boot.