> The X server is showing an 800x600 display resolution, but has > (apparently) decided that the screen can only display 640x480, this > leads to edges of windows running off the screen, etc.
I also had this problem and solved deleting all unwanted modes in XF86Config. So a line like Modes "1600x1200" "1024x768" "800x600" "1280x1024" "640x400" became Modes "800x600" It is not very elegant but it worked for me...:) I guess the problem is that X starts at the first mode listed and fvwm2 adopts the highest definition among all possibilities. You can also play changing the order the resolutions appear in the line... Good luck, Marko