Crashing on file selection dialogues after installing Win8.1

[KeithQ]

After upgrading from windows 8 to windows 8.1 Virtual Box is crashing on the file selection screen used when switching between disc images or importing an appliance. The smaller file selection dialogue used by the shared folders interface does not cause a crash.

If this happens from the VirtualBox Manager, then running VMs do not crash. If I try to change the cd image on a running VM, then that VM will crash.

Does anyone know what could be causing this? I've been working arround this by using VBoxManage from a command prompt, but it is very annoying.