[Freeswitch-users] Strange conference_auto_outcall_announce behaviour ?!

Hi, I am using python script and conference_set_auto_outcall application to make a conference group call. When I set "conference_auto_outcall_announce=conference/8000/conf-welcome.wav" in the dialplan, people joining the conference can hear the initial played back audio but can't hear anything else afterwards; people that joined the conference can be heard by the person that joined first. If I remove "conference_auto_outcall_announce=conference/8000/conf-welcome.wav" from dialplan, it all works. I'm using FreeSWITCH Version 1.4.26~64bit and default conference profile. The dialplan for this is pasted at [1]. Am I missing some configuration? Thanks, Stefan [1] http://pastebin.com/84tBFNmw