Oracle today released VirtualBox 4.0.4, a maintenance release of VirtualBox 4.0. It improves stability and fixes regressions.

This is a maintenance release. The following items were fixed and/or added:

VMM: fixed recompiler crashes under certain conditions (bugs #8255, #8319 and further)
VMM: fixed running 64-bit guests on 32-bit host with nested paging enabled on AMD CPUs (4.0 regression; bug #7938)
VMM: fixed timing issues / hangs for certain guests using the programmable interval timer (bugs #8033 and #8062)
VMM: large page and monitoring fixes for live snapshots (bugs #7910, #8059, #8125)
GUI: fixed error message when trying to exceed the maximum number of host network interfaces
GUI: fixed saving of changes to the metadata of an existing snapshot (bug #8145)
GUI: fixed rare crash on X11 hosts (bug #8131)
GUI: when selecting a shared folder, start the file dialog in the users home directory (bug #8017)
ExtPack: enforce the correct permissions which might be restricted by umask when creating directories (non-Windows hosts only; bug #7878)
VBoxSDL: fixed crash when starting by specifying the VM UUID (4.0 regression; bug #8342)
VBoxManage: allow savestate even if the VM is already paused
VBoxManage: fixed modifyvm --synthcpu (bug #6577)
VBoxManage: fixed hang when doing guestcontrol execute –wait-for exit and displaying process status on exit (bug #8235)
VBoxManage: decreased CPU load during guestcontrol execute –wait-for exit/stdout while waiting for the guest process to terminate (bug #7872)
VBoxManage: fixed list hostdvds/hostfloppies
VBoxManage: fixed storageattach for host DVD drives and host floppy drives
Metrics: introduced RAM/VMM base metric.
Main: improved sanity check when taking a VM screen shot (bug #7966)
Main: fixed a crash under rare circumstances if a VM failed to start
Main: fixed attaching of immutable disk images (bug #8105)
Main: fixed a crash at VM shutdown (bug #6443)
Main: fixed incorrect handling of cross-referenced medium attachments (bug #8129)
Settings: fixed truncating of big integer values (4.0 regression)
Settings: properly store the ICH9 chipset type (bug #8123)
Host-Only & Bridged Networking: fixed VBox DHCP server startup issue for Windows hosts (4.0 regression; bug #7905)
Host-Only Networking: re-create vboxnetX interfaces after vboxnetadp.ko module reload on Linux and Darwin (bugs #5934, #6341)
NAT: fixed an mbuf leak under rare circumstances (bug #7459)
ACPI: don’t allow the guest to enter S4 by default and don’t announce S1 and S4 in the ACPI tables if disabled (bug #8008)
Graphics card: made re-enabling disabled screens work correctly to prevent problems when X11 guests enter screen saving mode (bug #8122)
Storage: fixed write errors with snapshots if the host cache is disabled (4.0 regression; bug #8221)
ATA/SATA: fixed reset handling after ACPI suspend/resume
BusLogic: fixed hang with SMP VMs
Serial: another attempt to prevent lost characters during transmission (bug #1548)
Linux hosts/guests: Linux 2.6.38-rc1 compile fixes
Mac OS X hosts: fixed VBoxSVC crash when listing host interfaces without default gateway (64-bit hosts only; bug #7955)
Solaris/Darwin hosts: fixed VM CPU execution cap
X.Org guests: fixed a crash on X server restart (bug #8231)
X.Org guests: support X.Org Server 1.10 pre-release and Ubuntu 11.04 Alpha.
X.Org guests: Add EDID emulation in the graphics driver to prevent GNOME settings daemon changing the mode on login.
X.Org guests: never send graphics modes to the host that older VirtualBox versions can’t handle.
Linux Additions: fixed a memory leak in the shared folders code if a host link is not readable (bug #8185)
Windows Additions: fixed handling of Security Attention Sequence (SAS) with VBoxGINA