Recording to AMR using CMMFDevSound

Hi guys,
We're having a lot of problems trying to record and play AMR directly. Here is a small snippet of code of the initialization:

The recorder:
TRAP(initError, iMMFDevSound->InitializeL(*this, TFourCC(KMMFFourCCCodeAMR), EMMFStateRecording)); 

The player:
TRAP(initError, iMMFDevSound->InitializeL(*this, TFourCC(KMMFFourCCCodeAMR), EMMFStatePlaying)); 

It seems to record ok, and we write all the 32byte chunks into a file. However, when we try to play the recorded file we get an Error -2 in the player.

We have tried a ton of different options for the player and recorder, but nothing seems to work.

Does anybody have some working code we can look at - we'll really appreciate it..