[Users] Wrong URI in REGISTER

Hi fellows Our proxy is receiving some REGISTERs with wrong URI. The SOURCE PORT is inserted in it (the same number or incremented by 1). Our customers use Grandstream HT 486, 487. This problems is happening with 10 of them. This error happens just in REGISTER messages. If these customers make a call, they will talk without any problems. I can say this error isnt belong to a firmware version: some customers use the most new version and others of them use another. Did anybody already see this behavior? (running ngrep in SIP Proxy) U 201.58.X.Y:50142 -> IP_PROXY:5060 REGISTER si:50143p:domain_proxy.com.br SIP/2.0 Via: SIP/2.0/UDP 201.58.X.Y:50143;branch=z9hG4bKc5d3893e4a5ca0b6 From: <sip:3101@domain_proxy.com.br>;tag=148c0dd3bf6183fe To: <sip:3101@domain_proxy.com.br> Contact: * Call-ID: e72069564c2a8e01@10.1.1.4..CSeq: 11609 REGISTER Expires: 0 User-Agent: Grandstream HT487 1.0.6.7 Max-Forwards: 70 Allow: INVITE,ACK,CANCEL,BYE,NOTIFY,REFER,OPTIONS,INFO,SUBSCRIBE Content-Length: 0 --------------------------------- Yahoo! Messenger com voz - Instale agora e faça ligações de graça.