I am seeing this problem as well. (that computer is running Fedora, but I believe it's the same issue.)

lyall: unfortunately those tutorials aren't very helpful because the problem is that the orientation is correctly configured in xorg, and the gnome menubar and taskbar are correctly display in the first screen (the right screen), but the desktop icons are displayed in the second screen (the left screen).

A bug report has been filed but apparently it's being ignored:
https://bugzilla.gnome.org/show_bug.cgi?id=580366