I used to be able to do this to rotate the compiz cube:
Rotate desktop cube manually -> Ctrl+Alt+left-click the desktop and drag the mouse pointer
and it no longer works. Any ideas what it could be? My guess is that some effect I turned on took over the key/mouse combination but I looked through compiz config manager and couldn’t see where was.
I don’t know if it makes any difference but I do have one of these mice with extra buttons (7 in total I think) but I haven’t set anything special up for it.