Keeboard problems with Mandiva

Hi!
OK... So... I installed Mandriva.
When the selection menu comes up, to choose between Mandriva and XP, my keyboard is not active.
My keyboard does work as I can turn on/off caps lock and stuff before that boot screen, but not once it comes up.
So I repaired XP to be able to get into it again and used Acronis boot selector to choose between XP and Mandriva. Thats how I can log on XP now.
But when I try to load Mandriva it comes up with the same grub screen again and I can’t do anythingexcept to reboot.
Any idea that could help?