workaound for "unable to save prefs" Rated 5 out of 5 stars
I managed to get around the "unable to save prefs" bug by going to about:config and *manually* setting the prefs as needed. For example, if you want DeskCut to always prompt you for the shortcut name and save it to your Desktop, do this:
1) Set "extensions.deskcut.nameScheme" to "ASK"
2) Set "extensions.deskcut.deskPath" to "C:\Documents and Settings\[username]\Desktop"
Worked for me.