Yeah for that popup, if during playback if the orientation changes to portrait then back to landscape the "pop up" will be stuck there every time, at least until you click back then return to now playing, I changed the settings on mine to lock orientation during playback so that it can't reoccur.
I can't say I've delt with a crash yet but that hang issue I've noticed, but for me it's only when I close OVP that on the odd occasion it hangs in the background, for which a quick "killall openvideoplayer" in the terminal will remedy instead of rebooting.