I found something that could tell you whether or not the "X' button will work or not. During a stage press "select" then see if the "square" button will work or not. If not then most likely the X at the end won't either. Not sure if this is already known or not.
Also flickering screen during the beginning using US ver. ppsspp ver. 1.2.2
Also flickering screen during the beginning using US ver. ppsspp ver. 1.2.2