Hi!
Try to change the resolution in
/etc/X11/xorg.conf manually like below (change "Depth", "Modes" for your needs):
Code:
# **********************************************************************
# Screen sections
# **********************************************************************
Subsection "Display"
Depth 24
Modes "1280x1024" "1024x768" "800x600" "640x480"
ViewPort 0 0
EndSubsection