Ring tone does not work expected after transfer

Hi to all,

using asterisk NOW 1.5 with freePBX 2.5.1.0 & asterisk 1.4.22.
After transfering an internal/external call to an extention, the ring tone does not work as expected, it sounds continously like when you start a call. Tried to change /general settings/Asterisk Dial command options: (default is tr, tried t / tR / r /R etc) but nothing changed. Also checked from the logs that when the transfer is build the dial command is containing the right code like “tr”. Any ideas?