Comment 10 for bug 1283615

Also, if you do for some reason run g-s-d in Xubuntu desktop, it will reset your monitor configuration to defaults.

This bug appears to run deeper than just Xubuntu and nvidia, see for example: http://bernaerts.dyndns.org/linux/74-ubuntu/309-ubuntu-dual-display-monitor-position-lost

The solution is simple: if g-s-d cannot find a monitors.xml it should leave the display configuration alone. There is no reason to care about any other configuation mechanism the user might or might not be using.