My iPhone 3G always shows an Unknown number calling when I've got that person's contacts, What should I do?

That person is blocking his number so that it isn't transmitted via caller ID. The only thing you can do is ask him to stop blocking.

Are you talking about all callers, or a certain person. If all I would restart the iPhone by holding down the on/off and the home buttons at the same time until your see the Apple logo. if it is one person could it be that they have their number blocked. If not the I would call your service provide tech support.

Call your carrier. Apparently, you're not getting caller ID information sent from them. Your account may not be provisioned properly.

Are you saying that all incoming calls are displayed as "unknown", without any number showing, or with only the number, but no name even when the name is in Contacts assiciated with that number.

Then it's definitely a carrier problem.

If the phone displays "Unknown", it isn't receiving the expected caller ID #. If it says "Blocked", the caller is blocking the # from being displayed. If ALL of your received calls are "Unknown" there is a carrier problem. Contact your carrier.

Simmilar issue here!

Summary: Incoming calls show up only as phone numbers, not with the caller's name.

Steps to Reproduce:

1) On your iPhone, save a person's phone number in Contacts with the country's dialing code in front (+ZZZ-XX-YYYYYYY, where +ZZZ is the country code, XX is the carrier, YYYYYYY is the person's phone number);

2) Make a call from that person's device/number to your iPhone;

3) On your iPhone, while ringing, shows the above number without +ZZZ and without the person's name.

Expected Results: No matter how the number is saved (as +ZZZ-XX-YYYYYYY or simply as XX-YYYYYYY) the caller ID should always show up, as in previous iOS editions.

Actual Results: Caller ID does not work as expected and as in previous iOS versions.

Notes: When I receive voice calls, the number comes in without the country dialing code in front, simply appears as XX-YYYYYYY (where the XX is the carrier code and YY is the number) and the caller's name does not appear. In my address book ALL my contact's telephone numbers are preceded with the corresponding country dialing code, because i travel a lot. If I delete the country code from a contact's phone number, and that number calls me, then the person's name appears. I'm am in Angola (country code +244) using iPhone 4, iOS 5, carrier: UNITEL (92)

On the other hand, SMS's are OK, i.e. the Caller ID is linked to the phone number and shows up (because SMS's are receiver with the country dialing code in front of the phone number, p.ex. +244-XX-YYYYYYY).

It has something to do with the Carrier Settings Update as in iTunes i get the error message 1630 which states that: "iTunes could not check for un update to the carrier for your iPhone. An unknown error occured (1630)."

Thanks

dude i am having same issue, from Maldives, carrier Dhiraagu. this is something with iOS5 and i think iOS 4.3.5 works same like this. I hope Apple will fix this dirty lil thing asap.