Window resize bug in Vista's "Connect To" dialog

The "Connect To" menu option in Windows Vista Start Menu can be used to connect to a network. But I've noticed weird resizing of this window as shown in the following images.

Before:

After minimizing and restoring:

If this window is minimized and restored, then it's width increases! According to my observations, this happens very few times when Aero theme is enabled, but almost every time when using Windows Vista in Classic Theme with Themes service not running.