Mac mini runnning Mountain Lion (10.8.
The only things I have found to help is to completely shutdown all guests then cleanly shutdown VMware and restart. How to install Lion as a guest OS in VirtualBox 4 running on Mountain Lion I have: Legitimate owned copy of Install Mac OS X Lion.app Flash drive formatted as GUID partition, restored with InstallESD.dmg found and mounted from inside the Lion installer app using Disk Utility.app. My apologies if this is just re-stating the obvious, but did you remember to also install VirtualBox's latest Guest Additions (GAs) in your new Lubuntu guest VM? That would then actually "activate" the guest VM's related configuration and examining the 'GeneratedUID:' line in the output, or by just re-running that 'ls' command without the '-n' option - i.e.: 'ls -ATlOeR ' should show (in the two ACL lines) 'group:admin' instead of the UUID. In Virtual Box Guest machine, press the Host key + Del key to open Task Manager OR go to Windows Guest Machine menu and select Insert Ctrl+Alt+Del. The intermittent inability to copy/paste text from guest to guest, host to guest, or guest to host has been an ongoing problem for many versions.