asterisk users - Oct 2014 - ConfBridge / internal_sample_rate=auto / warning

Hi there,

I am running
Asterisk 11.9.0
WANPIPE Release: 7.0.10
DAHDI Version: 2.9.0 Echo Canceller: HWEC
libpri version: 1.4.12

When I start the ConfBridge application I get the following warning:

[2014-10-24 14:36:21] WARNING[29177][C-00006934]: config_options.c:790
uint_handler_fn: Attempted to set internal_sample_rate=auto, but set it
to 0 instead due to default)

I do not specify a specific user- or bridge-profile so the default
profiles are used in confbridge.conf (and there the profiles are empty).
But before calling the ConfBridge-App I set the channel var
"internal_sample_rate=auto".

Am I making a mistake or is it an indicator for a wrong configuration?

Best regards,
-Thorsten-