I'm running Ubuntu 12.04 LTS on Parallels 8.0.18354 (but this has been seen with previous builds) I have dual screens (laptop and a LCD monitor) with the Ubuntu VM extending across both screens. Often, when I'm moving the mouse pointer on the laptop (primary) screen, it will instantly jump over to the LCD monitor (secondary) screen. I don't know exactly how to trigger this but if you move your mouse around long enough on the primary screen, it'll eventually jump to the other screen. While not a show-stopper, this behavior can get annoying really quickly.
I tested similar Ubuntu VM running on VMware Fusion and the mouse pointer never jumps to the secondary screen. VMware Fusion 4 doesn't support 3D acceleration for Ubuntu. This is the only major difference between the setups.
I switched to unity-2d (no 3D acceleration) and the mouse pointer no longer jumps across the screens. This seems to be an issue with 3D acceleration environment and Parallels.
