Yes, a file configurarion file, like the rc.xml for Openbox. I have recently changed thanks a guy named mulberry in openbox channel. Is called mousebind or the alt+mouseclick buttons =P. In gnome is a choice in System-Preference-Window that you can change your option. For example if it's by default that presing alt, and a mouseclik to move a window in your desktop, you can use crtl super or alt in order to change it. I have used in gnome super key instead of alt. Xubuntu should have a module by the fwmv enviroment to overwrite that change of keys without going to the text file. It would be great.