Crazy problem since 4.3 update -- Custom locking AND rebooting?

[MikeGoob]

I'm using nova launcher thats it, not rooted.

Once in awhile the screen shows an open lock symbol under a SAMSUNG logo and the word CUSTOM under the lock. The buttons all fail to respond, then the phone does the blue swoop and seems to reboot, show the verizon logo and everything looks/works normal right away. Did it really reboot?

Sometimes when not touching the phone it suddenly makes a 'reboot' sound with the piano music, then the verizon logo and a reboot happens.

In both cases, it seems like it's not REALLY rebooting because everythings ready to go as soon as it's done. but either way... HELP!

 

[wardo]

This reboot thing happened last night when I was messing with my wife's s4. I don't think it was a reboot since it was ready very fast.
Kinda weird.

 

[MikeGoob]

Here is a terrible pic of it. it says "SAMSUNG"... you get the picture

Any help?

<img src="http://i42.tinypic.com/23jl734.jpg">