Windows 7 VirtualBox Admin GUI Hang

[leakybucket]

Windows 7 64bit
VirtualBox 4.3.10

I've had some strange behavior start recently. When I try and start VirtualBox.exe it hangs with never displaying the UI. I can see the process is running, but the UI never shows up. This started happening with 4.3.6, but continued after I installed 4.3.10.

Has anyone else seen this behavior?
Is there a way to start VirtualBox in verbose mode?

Thanks!

[leakybucket]

VBoxManage also hangs when I simply try and list the vms. So I assume VBoxSVC is hung somehow.