Left rotated display one pixel too wide

[Tobias Ringström]

I'm using a dual rotated 1280x1024 monitor setup with Fedora 12, and 
there a funny little issue with the display size, or rather applications 
idea of display size, because both the desktop background and the GNOME 
Panel protrude one pixel into the right display.

It's not really a big problem but it's a little annoying, both because 
it looks bad, and because the extra panel pixel interfere with window 
movement on the right display.

Any idea of how to investigate further, or where to file a bug report?

/Tobias