Package: xbase-clients Version: 4.3.0.dfsg.1-1 /etc/X11/xinit/xserverrc calls X like that: 'exec /usr/bin/X11/X -dpi 100 -nolisten tcp'
The '-dpi 100' bit is wrong. It overrides anything you might have written in the config file, which is very annoying. The config file has a way to specify the screen size. The config file is the correct place to put this information. The commandline in some script is _not_.