Series60 Socket Example on Orange FR

hi !

I'm facing a curious problem with the Socket Example provided with the Series60.
I'm running a Java Programm that is playing the role of the SocketServer. This programm works fine.
Then I launch my Socket Application on my 6630. The programm tells me it's "Connected". But nothing can be sent from my Mobile to my Java Prog, although IP address are correct.
I find this also very strange because i can only configure the 6630 to send on port 80, any other port won't tell me that I'm "Connected" but will generate a TimeOut ( I have also change the port number on the java app ).

My question is : can this problem be due to my network supplier ? I have Orange France ( Prepaid cards/Mobicarte). I even tried to bypass the Orange proxy settings ( 192.168.010.010:8080), my Socket prog tells that I'm "Connected" but nothing can be transmitted from the mobile phone to my PC.
I really can't figure out what could be wrong:-(

Thx a lot in advance !

MatD:-)