sems transparent sbc contact problem

[pumper]

Hi I am new to sems and I want to use it as sbc in transparent profile. my problem is that for the REGISTER message I used: enable_reg_caching=yes
but contact header that sent to the sip proxy server is something like :
Contact: sip:[email protected];transport=udp;expires=600
I mean sems change user number to a hash string. but my carrier proxy server after registeration don't send calls to the user because it cant find the user. how to resolve this? I need the contact to be with user number for example
Contact: sip:[email protected];transport=udp;expires=600
every change i made in the configuration file dosnt affect contact header.