I am a refugee from the Gnome3 madness and have loaded Xfce4 on Mint 14 in search of a more friendly (to me and my curmudgeonly ways) work environment.
I have tried several methods to do the above based on Googling and past experience with Xfce with no persistent success. I have used both the xmodmap and setxbkmap methods to make the swap from a terminal command line. This works but of course needs to be redone every time I login.
I have determined that xmodmap is executed without error by /etc/xdg/xfce/xinit, yet when my session is up and ready for use, the swap has either been undone, or didn't take effect in the first place.
This key swap is commonly done. I have found several posts about this problem with Xfce and none with a verified solution. This is getting very old and I have wasted many hours at this. Earlier versions of Xfce had this as an option in the setup menus but it seems gone now.