Comment 1 for bug 330258

Thanks for your bug report.

I assume you have an nVidia card. This currently happens when an error occurs in loading the nVidia backend and disper falls back to the XRandR backend which hasn't import implemented. DISPLAY should be ok, or disper should complain about not finding a backend.

Could you include the output from disper as run from the udev script with verbose output (add -v to commandline)?
To see better what's happening, please save the attached file somewhere and run it from the udev script (with DISPLAY set correctly).