It is easier to call in. This happened to me 2 weeks ago.
go to HKEY_CURRENT_USER/ControlPanel/Phone
under it, you should able to see a key name "CallIdMatch", change the value to maybe 8 or 9, which means it will match the last 8 or 9 numbers for each incoming call or sms. (use decimal) after the changing, reboot your phone.