problem with receiving stream

hello,
I have a "little" problem!
After the authentication phase it's all ok, when I receive a call from
a telephone, the client receive the INVITE request, send the OK
response, and receive the ACK.
After, the telephone send me a OPTIONS Request, and only when the
client send a NOT ALLOWED Response, the transmission  from the client
to the telephone start, but the session listener, the
receivestreamlistener etc... not receive nothing from the telephone to
the client.
I don't have any idea what is the problem. I have tried to set many
audiocodec in the sessiondescription, modify the timetolive, but
nothing.
best regards,
max

-- 
Centorame Massimiliano
Undergraduate Student of Computer Science University - Bologna (Italy)