changing XFCE keyboard shortcuts in Mandriva 2009
I want to change the keyboard shortcuts that come along by default in XFCE4. For example Alt+Esc is set to "xset dpms force off". I want to disable this and use Alt+Esc sequence for StumbleUpon in Firefox. However when I open the shortcuts dialog box from xfce menu > Settings > Keyboard Shortcuts, I find that all the options are greyed out, and hence non-editable. Now since I use Alt+Esc sequence for StumbleUpon in all other distros as well as for Gnome and KDE in Mandriva, I hate to have to change this sequence for XFCE4. Is there any solution for this?
Thanking in advance,