Since my install of WP 8.1 had to do two soft resets on my phone due to lock up.

[vonskie]

Anyone else have this problem?

This is on my 1020.

Seems to happen when I try to wake it up, It does not respond to anything but a soft reset.

 

[DDinFTW]

I also had this problem with my 1520 but they have since gone away, fortunately...I found that recent new apps caused it one time. FYI, I was able to wake it up using the camera button (quirky I know).