1) Put guest to sleep.
2) Wake guest from sleep.
3) Move mouse to upper left hand corner
4) Switch to uivm
5) Move mouse to the lower right hand corner
6) Switch back to guest
7) Note the mouse remains in the upper left hand corner
Normally the mouse pointer would match the last location of the uivm before the switch if Xenmou is loaded, and vice versa. Disabling and re-enabling the driver within Device Manager returns it to a working state.
OpenXT with Windows guest with PV drivers installed