I'm annoyed by folks (including employees of VMware) saying that VMware Fusion 4.1.3 works fine on Mountain Lion. I have an early-2011, i7 MBP with 8 GB of RAM and an external monitor attached. When I launch a VM and make it full screen on my external monitor, any other windows I have on my main laptop screen flicker and jump like crazy. If I drag the windows from my laptop screen over to the external monitor with the VM, the jittering stops. When I move the windows back to my laptop screen, they jump again. The top menubar on my Mac laptop screen also jitters and flickers when a VM is run full screen on my external monitor. When I command-tab, the app switcher flickers and/or freezes on my laptop screen when VMware Fusion is running on my external monitor. As soon as I shut down the VM and quit VMware Fusion completely, all of the abnormal behavior immediately stops. Hoping VMware releases a fix shortly. I'm annoyed that they had access to the GM for weeks and didn't fix this issue prior to the public release of ML.