I have posted a couple of notes about trying to use multiple
resolutions in my XF86Config with the VIPER VLB card and
getting the error :
(--) P9000: The dimensions of 640x480 do not match those of the
first valid mode.
(--) P9000: Removing 640x480 from list of valid modes.
I sent the problem to Erik Nygren, the author of the P9000 server
and this is his response :
The P9000 server can only deal with one resolution (ie either 640x480
or 1024x768 but not both) at a time. The Modes line :
Modes "1024x768" "640x480"
is looked at and all modes with a different resolution
(screen dimensions) than the first valid one are removed.
Virtual 1024 768
is ignored because the P9000 server can't deal with
hardware virtual screens. This is a limitation of the
Hope this information is of use to the Linux user community.