With the first beta version I just had some problems, where Multiplicity seemed to have lost connection and had to be stopped via Ctrl-Alt-End, but not very often. Just upgraded to 1.01 and don't get it to work anymore. Moving the mouse over to the secondary machine makes the mouse pointer disappear on the primary machine, but not controllable on the secondary. Moving it back onto the primary machine then doesn't work anymore, the mouse-pointer is "lost". At that point, I have to end Multiplicity.
Primary Machine: Windows 2000 Server, SP4
Secondary Machine: Windows XP Pro, SP2
Using a Microsoft IntelliMouse via USB and the original OS drivers for it.
Hope you can give my some idea to get it back working again, I already felt so comfortable with this setup