Oracle’s VirtualBox 4.0.10 is now available for download. This is just a maintenance release. It improves stability and fixes regressions. VirtualBox is a powerful x86 and AMD64/Intel64 virtualization product for enterprise as well as home use.
Some fixes are
Windows hosts: fixed leak of thread and process handles
Windows Additions: fixed bug when determining the extended version of the Guest Additions
USB: fixed occasional VM hangs with SMP guests