Stuck GUI on importing VM

[dan_fonleap]

First, thanks for creating a fantastic product! We use VirtualBox for almost everything.

Just reporting a small problem with the GUI when importing VM, in file-selection dialog box.

VirtualBox: 4.2.8, seen in 4.2.1 and later as well
Host: issue seen on Macbook Air, Mac Mini, Macbook Pro in Snow Leopard and in Lion
Guest: N/A
Guest additions: N/A

To reproduce:
1. File->Import Applicance
2. Click 'choose'
3. Click on another Application, or even on the plain desktop, so that VirtualBox is no longer in 'focus' as the primary application.
4. Click back on the VirtualBox file dialog box.

This causes a separate file-selection dialog box to pop up, hiding the previously open one behind it. However this dialog box cannot be used and 'cancel' does not work on it. The rest of the VirtualBox GUI is locked as well. The only recovery mechanism seems to be to force kill VirtualBox from Activity Monitor.