[Asterisk-Users] double ringing tone on asterisk 1.2

[Simone Cittadini]

While I wait for the call to be answered I hear a "double ringing tone", 
like :

expected tone :
tuuu         tuuu         tuuu         tuuu

what I hear :
tuuu tuuu   tuuu tuuu   tuuu tuuu   tuuu tuuu

the second "tuuu" I think is generated somewhere and not "true", since 
it sounds slightly different and the lambda between the first and the 
second is always different.

the problem appears no matter where I terminate the call (IAX or Zap), 
and I don't have that problem on a 1.0.7 connected to the same PRI lines 
and IAX servers , what I have to check ? looked in confif files but 
appears to be the same (indications, modules loaded, iax, zapata, the 
dial in extensions is the same)