Comment 7 for bug 838714

I haven't been able to make this happen in a VM for testing. My best guess was that it might be possible to trigger this by making sure that those two .desktop files have identical mtimes, but that doesn't seem to trigger it for me. Perhaps it's also resolution-dependent, though, as something like this would explain why you don't see this every time.

In any case, as far as I know, casper has no direct control over this; it just drops some files into place in /home/ubuntu/Desktop/. nautilus is responsible for drawing the desktop, and anything we do in casper would at best be a workaround. Reassigning over to nautilus and the desktop team.