I am now seeing what appears to be a window that you can see through but there are black horizontal bars along the top and bottom of the screen. If you see this you can not do anything on the screen except press home to knock out this empty window.
If this window is showing and your alarm rings you will not be able to snooze or off the alarm. The same with calls.
If you press the home button on either of these it gets messy quick. with the alarm, it keeps ringing while you dig around trying to figure out how to shut it off. If you get a call and you press home then that causes the call to stop ringing. The popup ads were one thing but this is pretty bad.
It has to be a new bug with pie.