A most irritating bug whereby windows will jerk and lag when attempting to move them, either after compiz has been running for a bit, or just after a viewport/workspace change.
The problem appears to be something to do with mouse polling in compiz, and the fix is to limit the rate at which your mouse can be polled.
Following the solution posted here:
sudo gedit /etc/modulesAdd the following to the end of the file:
-r usbhidSave and reboot. Hopefully moving windows is now back to being smooth!