Comment # 19 on bug 971885 from Felix Miata

Comment 2 failing Intel gfx hosts gx260, gx28b and gx760 join host gx780 in
failing to respond as expected (1680x1050@108DPI) to 'xrandr --dpi 108 --output
VGA1 --mode 1680x1050', instead inheriting 1440x900@96DPI from bootloader
kernel cmdline parameter 'video=1440x900@60' in

    IceWM

session, whether started from startx or from KDM, *unless* some other xrandr
command precedes 'xrandr --dpi 108 --output VGA1 --mode 1680x1050' in the
startup script. Host gx780 differs only in using DisplayPort connection vs. VGA
for the other 3.

Thus, this has nothing to do with KDE*.