You are stuck with Ctrl+Alt+Del and cancel Excel task only as a last resort,
you can usually manage to break loose. Unplugging and reattaching
the mouse is one I'd not thought of before.
http://www.mvps.org/dmcritchie/excel/ghosting.txt
As far as Microsoft not recognizing the problem, it is a matter of
coming up with a worksheet or a sequence of repeatable events
that can cause the problem anywhere, any time.
I haven't had ghosting problems for a long time, but I do get have
the red light go out on the (USB) mouse and have to unplug and reattach
it into the USB hub. I know of others that have this problem and
I don't think this one is limited to Excel. Location within the hub may
have some inpact on the frequence.