I've tried to upgrade from RC5 to RC6, I didn't "Wipe Data & Factory Reset", just "Wipe cache & Dalvik cache" .. after reboot, the WI-FI keep re-connecting ... I haven't tried to do "Wipe Data" before updating coz this is very time consuming to reinstall everything .... so I fall back to RC5 from my backup, then the WI-FI works fine again.
I suppose updating between minor version doesn't require "Wipe Data" ... right?
Change your camera application settings. Use 4mp and super fine quality. That should stop the camera from locking up. Also, update to at least the version that had camera fixes in the release notes. I forget which one that was.