VirtualBox Strangeness: Touchpad Click Doesn't Always Count

I have yet to upgrade to VirtualBox 5, so this issue may actually be resolved.

I noticed while working with VirtualBox that the manager program's UI doesn't always respond correctly to clicks that I make by pressing down with my stylus onto the touchpad. For instance, clicking on the Settings button in the toolbar makes the button look pressed-in, but nothing actually happens unless I click by pressing the dedicated "click" button on the touchpad.

Also, clicking on the X button on the "there's a new version available" message box does the standard press animation, but the box doesn't close unless I click OK. Huh.