This following link shows a possilbe answer to your problem.
I had that trouble as well, but that appeared after the installation
is complete using Mandrake 9.1
It had either something to do with the memory being bad,
packages installed had some errors, or even the partition of the
hard drive was done incorrectly. I found out that when installing
Mandrake 9.1, the partition must be unallocated space.
The link below shows the computer I worked on with unallocated