Any VBox 4.3 guest VMs just stuck in full screen mode => Fixed in SVN
Host: x64 Ubuntu v13.04 with installed "virtualbox-4.3_4.3.0-89960~Ubuntu~raring_amd64.deb"
Guest_1: Xubuntu v12.04.3
Guest_2: Windows XP
Problem: I can't minimize any guest VM which is switched in full screen mode by pressing "Minimize" button it the menu bar. VM just blink and stay full screened. So I can't access to the host PC screen. :(
Any other VirtualBox v4.1.x, v4.2.x doesn't have this bug!
Please, fix it in the v4.3.x bunch.