Please contact your TAC… It’s really difficult for me to “discuss” about problems like this with an operator.
I must emphasize that the issue is not due to ALU equipment, but due to a mistake in the standards. Probably.
The problem itself *might* lie in ETSI DTX VAD2 algorithm, which is not compatible with AMR, as far as i know.
Let us know as soon as the TAC have any news 🙂