Hmm.... the plot thickens. I noticed by listing /etc/X11/XF86Config-4 that there is no 1280x1024 modeline, even it I specify it at the boot prompt. Indeed, there is no such line even if I choose "expert" booting and configure X by hand (deselecting all resolutions except for 1280x1024 in the Screen section)!

Any ideas? BTW, I *can* write to /etc/X11/XFConfig-4 (I tried adding a comment line with vim, just to be sure...)

M