hang on windows after update notifier window pops up

[jetpilot]

i was using a relatively recent VirtualBox version on Windows 10 and was sending my host machine to sleep (as it works quite nice all the time). after a wake up VBox brought up the notifyer dialog for a new version beeing available on the internet for download. (not sure if that dialog is normally modal or not - but it would be better if its not!) at this point i was no longer able to control the main application and neither the currently running VM window. neither keyboard nor mouse input were able to interact with any of the two main windows and (BAD THING HERE) not even with the update notifier pop up windows.

(closing either of this first with a task manager did not cure the situation for the other window.)