I got my Nexus 4 today upgrading from a Galaxy S, and I noticed that with the current nightly I have the following issue:
Starting the camera I dont have continuous focus, tap to focus works though.
When I activate HDR and tap to focus once, continuous focus starts to work afterwards. Now I can switch off HDR again and continous focus keeps working, until I close the camera.
I do not have the crackling-noisewhen-focus issue, though (googling the continous focus issue I found several postings that suggest a connection, which I do not see).
I'm on .33 radio, will test .48 next ...