How did you install grub?
What exactly is the error? Is it freezing up after it tries to start? Do you get a boot menu?
Did you set it to the master boot record? And what hard drive did you install it on?
From what I understand, grub can be set to your master boot record of your first hdd in bios. Also, if you are setting it up with a graphical window it needs to point to the splash screen and correct linux kernels.
If you are manually trying to install grub I find the Gentoo tutorial very helpful.
You can find it here: http://www.gentoo.org/doc/en/handboo...part=1&chap=10