Polycom IP 335 can`t use TCPonly talk to server

Hi,

I try to set our IP 335 work as TCPonly mode, but it won`t work. I can provision the phone and TCPonly has been select throngh view the web interface. But, when I check at server side, the phone still talk to our server through UDP. I try unplug the power and reboot the phone, it still use UDP.

Phone Model SoundPoint IP 335             SIP Software Version 3.3.3.0069 BootROM Software Version 4.3.1.0440

<voIpProt.SIP voIpProt.SIP.enable="1">      <voIpProt.server voIpProt.server.1.transport="TCPonly">      </voIpProt.server>      <voIpProt.SIP.outboundProxy voIpProt.SIP.outboundProxy.address="myserver.com" voIpProt.SIP.outboundProxy.port="5060" voIpProt.SIP.outboundProxy.transport="TCPonly">      </voIpProt.SIP.outboundProxy>    </voIpProt.SIP>  </voIpProt> <reg>
reg.1.server.1.transport="TCPonly"</reg>

Please help me! Thanks

Regards