Virtue seems to be based on Desktop Manager.
[link|http://virtuedesktops.sourceforge.net/|Virtue].
I don't know if it works better with the MacOS default keys, but since it's still under development you might have more luck with it. (DM says "0.5.3 has been released. This is identical to previous releases except that the minimal amount of work done to make it Tiger-compatible has been done. Please do not ask for more features to be added as I am no longer developing the 0.5 branch." It's not clear what that means exactly.)
[link|http://docs.blacktree.com/doku.php?id=quicksilver:what_is_quicksilver|Quicksilver] might interest you too. It claims to be a framework for working with MacOS more efficiently. It has [link|http://quicksilver.blacktree.com/docs/?page=Mouse+Triggers+Plug-In|mouse triggers] that can work with Virtue if you do [link|http://virtuedesktops.sourceforge.net/help/html/solvingproblems/spQuicksilver.html|this].
Note I've not used either of these things. Please report back if you find them useful.
HTH a bit. Luck!
Cheers,
Scott.