mercer is not mentioned in Mdv HCL
http://www.mandriva.com/en/hardware
but an old bug similar to yours does exist for a diff hw
https://qa.mandriva.com/show_bug.cgi?id=26083
but this may not be the only issue.
there are a couple of ways of seeing if this is one of the issues.
assuming you installed grub at mbr...when grub starts press escape to stop timer.
go down to the line you want to run and press E for edit.
press the right arrow or left to navigate to options
kernel /boot/vmlinuz (version) root=/dev/sda1 .....options are here
I do not have a laptop but delete all options except you will add in
noapci
then escape and press enter and see if it boots....if it does with no further errors you need to make that permanent change.
However, when you installed....did you choose a laptop kernel?
so once booted install laptop kernel and make that your default boot.
2) If you can not get in that way....let me know if you have a live cd or just the install cd....and name what you have pls.