GRUB Loading. ; error : out of disk ; grub rescue>

[Evaris]

Hi ! Absolute beginner with Linux, using the Ubuntu 9.10 live CD, I've installed it on 3 machines without any problem and the users are very happy.
Unfortunately with my old laptop after install and reboot :
"GRUB Loading. ; error : out of disk ; grub rescue> "
What can I do ? I'm not familiar with line commands.
Any help would be much appreciated thanks.

[Leppie]

this may be related to this bug: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/477430
also, what partition is ubuntu on? remember that old systems cannot boot beyond cylinder 1024 (this can be circumvented by creating a /boot partition in the lower regions of the drive).