Comment 36 for bug 413348

Okay, I have the same symptom from the following arrangement:

I have two displays, a secondary 1600x1200 screen on VGA to the left, and a primary 1920x1200 display via internal DVI to the right. The graphics are handled via the Nvidia driver, and the multi-display setup configured via the nvidia-settings app with the 1920x1200 display marked as primary

GDM displays only on the primary screen (the secondary screen is initialized & running at the correct res, but is blank)

Xsplash is rendered at 1920x1200, but is positioned from 0x0 (i.e. the far top-left corner, on the secondary display) rather than either spanning both screens or covering only the primary display