I still have this issue. The audio quality randomly gets bad, and makes it very difficult to have a conversation. This was one of the main reasons I purchased this phone in the first place, and it has been nothing but problems (sorry, just venting).

I have tried the packages listed at the top of this pages, several different codecs, locking the frequency, and several other things, but have gotten nowhere.

Does anyone have any ideas / does sip work with no problems for anyone?