Softphone : caller id OK, without name


Asterisk sends correctly inbound’s callerid to all of my hardphones (Siemens SL560 & S450IP), and my softphones (X-Lite and Zoiper). The Hardphones display the name of the caller instead of the number, as soon as the caller is in the adress book. The Softphones display only the caller’s number, and never his name, even when it’s in the adress book.

Did I missed a special softphone’s configuration in sip.conf ?
Could you help me to find fix this issue ?

Thank you.

NB : I am using Asterisk 1.4.18, Zaptel, X-Lite v3.0 build 41150, and Zoiper 2.1.4.