VirtualBox 2.2.2 Changelog:
Host and guest clipboard: fixed a number of issues affecting hosts and guests running the X window system.
Guest Additions: make sure the virtual mouse autodetection works on first reboot after installing the Additions on X.Org server 1.5 and later.
Guest Additions: properly report process identity number of running services
Guest Additions: clean up properly if the X Window server terminates
Linux Additions: fixed installation path for OpenGL libraries in some 64-bit guests (bug #3693)
Solaris Additions: fixed installation to work when X.Org is not installed on the guest
Solaris Additions: fixed a bug that could panic the guest when unmounting a busy shared folder
Windows Additions: fixed mouse pointer integration of some Windows guests (2.2.0 regression, bug #3734)
Windows Additions: fixed installation on Windows Server 2008 Core (bug #2628)
Main: do not try to use older versions of D-Bus (Linux hosts only, bug #3732)
VMM: fixed out-of-memory conditions on Windows hosts (bug #3657)
VMM: fixed occasional hangs when attaching USB devices during VM startup (2.2.0 regression; bugs #3787)
VMM: fixed guru meditation related to memory management (software virtualization only)
Virtual disks: fix possible data corruption when writing to diff images, incorrect detection of redundant writes
GUI: reworked network settings dialog
GUI: properly show the detailed settings dialog of NAT networks (bug #3702)
GUI: HostKey could not be changed (2.2.0 regression, bug #3689)
GUI: fixed memory textfield size (Windows hosts only; bug #3679)
GUI: fixed crash when selecting a shared folder path (Windows hosts only; bugs #3694, #3751, #3756)
VBoxManage modifyhd --compact: implemented again for VDI files, and now supports relative paths (bug #2180, #2833)
VBoxManage snapshot discard: made it work again (2.1.0 regression; bug #3714)
NAT: on some Windows host, the guest didn’t receive a DHCP lease (bug #3655)
NAT: fixed release assertion during poll() (bug #3667)
Clipboard: fixed random crahes (X11 hosts only, bug #3723)
Shared Folders: fixed incorrect permissions for Solaris guests
Shared Folders: fixed wrong file sizes with Solaris guests
CBindings: fixed possible memory leak while releasing the IVirtualBox and ISession Objects
Solaris hosts: fixed host-only network interface incompatibility with nwam/dhcpagent (bug #3754)
Windows installer: fixed several install and uninstall issues (bugs #3659, #3686, #1730, #3711, #3373, #3382, #3701, #3685, #3710)
Mac OS X hosts: preliminary support for Snow Leopard