Default [Q] Wifi most of the time cannot start (not displaying list), restart sometimes helps

Hi!

Since last 2 weeks I'm suddenly experiencing weird problem without making any changes in the phone.

The problem:
When enabling wifi it freezes in wifi settings page (whole Settings app is freezing and needs restart). Not displaying list, just "enabling wifi..." message and app freezes in that moment. Waiting very long dosen't help. Phone is draining battery incredibly fast in that condition.
1. Switching Wifi On/Off - works.
2. when starting the phone - sometimes wifi starts and works,
3. when loosing wifi signal of connected network (going from place to place) - always wifi freezes and stopps to work.

I've done factory reset, cache format, I'm using CM 10.2-201312221-NIGHTLY now and before I've used stable cm-10.1.3. No difference. Is there a way I can solve or debug the issue?

Thank you very much for help!