I have exactly same issue. I have a bury hands free kit for the 3109c.
Worked fine with version 7.00 software , ever since I have updated to 7.21
volume is so low when using hands free kit that it is unusable.
The Nokia software suite software only seems to let you download latest software version
anyone know how to obtain previous software versions? e.g. 7.00
I have been driving 8 months now thinking that the Bury carkit was broken. Now it's replaced and still my volume is way to low. I also have firmware 7.21
did you solve the problem ?
Hello, luckily my phone supplier replaced my Nokia 3109c with an phone that contained an earlier version of firmware (7.00) they said it was a known issue with the firmware.
I contacted Nokia support regarding this but they were not any help and said there was no way to downgrade firmware on the phone.
hope this helps basically you need v7.00 firmware or lower with the Bury kit