[Wylug-help] Grub boot menu screen unreadable

[roger]

Hi.

I've just, successfully, installed F18 alongside Win 7 on a Thinkpad 
T400. Clearly Grub is trying to show a boot menu, since I get different 
boots if I just press [Enter] or down arrow first). The problem is that 
the screen is mangled: shaded coloured lines with some dots.

It would be nice to be able to read this menu. Can the problem be fixed?

NB Once Fedora itself starts to load, the display is perfect.

/etc/default/grub is:
---------------------------------------------------------------------------------------
GRUB_TIMEOUT=5
GRUB_DISTRIBUTOR="$(sed 's, release .*$,,g' /etc/system-release)"
GRUB_DEFAULT=saved
GRUB_GFXMODE=640X480
GRUB_CMDLINE_LINUX="rd.lvm.lv=fedora/swap rd.md=0 rd.dm=0 $([ -x 
/usr/sbin/rhcrashkernel-param ] && /usr/sbin/rhcrashkernel-param || :) 
rd.luks=0 vconsole.keymap=us rd.lvm.lv=fedora/root rhgb quiet"
GRUB_DISABLE_RECOVERY="true"
# GRUB_THEME="/boot/grub2/themes/system/theme.txt"
---------------------------------------------------------------------------------------

On advice from someone on the Ask Fedora site, I commented out the 
GRUB_THEME line and added the GRUB_GFXMODE line - and ran,
sudo grub2-mkconfig

Thanks,

Roger Beaumont