Me too I'm using a Betamax service (the company behind voipcheap & co.) and the iLBC fix did the trick.

I would like to underline the great flexibility of rtcomm compared to other Voip implementations, like the one of my N82. You can make various profiles (related to many accounts) and have them working together without the use of an asterisk server. This means that you can easily switch from one to an other an you can always receive calls from all of them. The latter is particularly useful with betamax products, since you are not allowed to call from a voipcheap account a voipbuster one (or at least i couldn't easily).

Best regards and enjoy a great voip device!

Mattia