I have a problem with my BT 6510 phone. Caller ID is activated and appears to be working OK. Calls to/from most numbers are displayed with the name, as listed against the number in the Contacts list. However, some calls always appear as just the number. (I have carefully checked the Contact list numbers - there is no mistake.) The fault occurs when I make a call to or when I am called from the problem numbers. Any ideas what is wrong here? Do I have a faulty phone or is it the "national Caller ID problem" again in a different guise?