VirtualBox 4.3.18 is a maintenance release. The following items were fixed and/or added since VirtualBox 4.3.16: VMM: fixed a potential misbehavior after restoring the A20 state from a saved state GUI: fixed full-screen mode mini-toolbar related regressions for different platforms and window managers (bug #13369) GUI: X11: fixed full-screen mode Unity panels quirk caused by mini-toolbar code changes in last release (bug #13365) GUI: X11: added possibility to use legacy full-screen mode as the new one can cause multi-screen issues under Unity, see the manual for more information (bug #13365) GUI: Mac OS X: fixed full-screen mode artifact causing black screen when 3D acceleration was enabled on 10.10 Yosemite hosts (bug #13448) GUI: Mac OS X: fixed regression in user-space swiping from/to VBox in full-screen mode GUI: Mac OS X: fixed issue with switching to VBox in full-screen mode through Alt+Tab and Mission Control Storage: fixed data corruption when resizing huge VHD images under certain circumstances (bug #11960) Storage: fixed a rare hang during startup when the BIOS enumerates the storage devices attached to the SATA controller Storage: follow the spec with AHCI interrupt acknowledge (bug #13474) Storage: fixed broken iSCSI authentication (4.3.14 regression, bugs #13386, #13435) NAT Network: properly parse port forwarding rules to allow UDP rules USB: fixed a crash on Linux hosts with older Linux kernels (bug #13400) and several other fixes ACPI: fixed ACPI timer anomalies (bug #12076) Guest Control: fixed a memory leak (bug #13434) Main: when removing a VM, do also remove the VBoxStartup.log file which might exist on Windows hosts (bug #13478) Windows hosts: fixed more startup problems on certain Windows hosts due to conflicts with anti-virus software; better error reporting (4.3.14 regression; bug #13187) Windows hosts: propagate the process startup information to the child process (4.3.14 regression; bug #13243) Mac OS X hosts: don't force using the discrete GPU (bug #11111) Windows Additions: some Windows 10 tweaks X11 guests: fix a bug handling video driver display properties which prevented GNOME Shell on Fedora 21 from starting Linux hosts / guests: fixed a few remaining warnings in the kernel log if memory allocation fails (bug #11171)