Fact: Workstation dual boot Suse Linux and Windows XP, bootloader: GRUB

Problem: After installation of Novell ZEN 6.5 agent the workstation keeps
rebooting and the GRUB-menu won't show.

Cause: I think Image Safe Data info corrupts Grub.

When i start the Suse installation and choose for Repair => Bootloader
Configuration is can repair it until . . . i start Windows. After shutting
down Windows the problem is back.

What is the real solution besides not booting Windows ;-)

Don't be cryptic in your answers please.

Thanx in advance!