Thomas H. George wrote:
Quote from /etc/default/grub: "...you can only use modes which your graphic card supports via VBE you can see them in real GRUB with the command vbeinfo."
Besides what Tom suggested if you have "hwinfo" installed you can run as root 'hwinfo --framebuffer' and get the vga codes for your video card and add it to the grub kernel line as 'vga=code', replace code with the right code for you system.
-- Jimmy Johnson Debian-Live - Sid - KDE 4.4 - installed at sda14 Registered Linux User #380263