CCV freezing up was/is definitely a problem on the M62. The 4.4 and 4.6 share the same CCV parts.
For the M62, there is a heater kit that wraps around two of the CCV hoses. My local dealer swore it didn't exist, but ECS Tuning sold it, and the part number does really exist.
Look on this thread for some of the service bulletins and parts.
http://www.xoutpost.com/bmw-sav-foru...under-cpo.html