T21P E2 can't register(stuck at Registering ..)

[myombo]

Hi,

I am having two phones(T21P E2) which can not register.
I have tried with different firmwares(52.80.0.60 and 52.80.0.70) with no succes.

I have analysed the SIP messages and everything seems to be ok but its like the phone doesn't understand the "200 Ok" for registration.In my registrar server i can see my line registered(and i can receive calls) but the account status(at the phone's web interface) stays at registering(Not registered).This leads to the message "No service" on the screen and as a result i cant make calls.

I have attached the files, config.bin and pcap(log level 6) file for analysis.

Thanks in advance for your help.