I'm happy I've come across this thread.

I'm having the exact same issue as panjgoori. The screen started to flicker today (even in my pocket, got a lot of apps opened and shortcuts deleted by itself). It will often flicker by it's own : I mean the phone is on the table and the screen unlocks by itself and then 1 second later locks and again unlocks (like a lot of times) and then just locks. And also the battery is draining really really fast because of the flickering.
And the same thing as described by panjgoori happens with backupmenu, it restarts after the menu is showed.
I didn't drop it lately, I mean the last time was like 6 months ago and it worked fine until today.
I hope it is moisture, but in the country I am no repair shop wants to open it to clean it. They say it is too complicated because of the slider mechanism and it is not worth it. I would do it myself but I don't have the necessary skills.
This weekend I will try some other repair shops and I hope someone will be willing to take a look at it.