Strange Windows Mobile fault: Phone application shows wrong name... Or not?
I have a friend in Wellington, New Zealand, let's call her L.E. with phone number +64 4 555-1234. I have a commercial contact in Auckland, let's call her R.M. with phone number +64 9 555-1234. Yes, same country code and phone number, just different area codes.
An interesting coincidence.
Today R.M. called me. I answer saying "Hello L.E."... But of course it wasn't L.E calling me, but that's what the Phone application tells me.
It seems the Windows Mobile Phone application searches only the phone number (not including the area code). It also seems the index use is probably something like (Phone + Name), therefore a search with Phone = 555-1234 brings L.E.'s record first - and stops there without checking area code to make sure it's really who the caller is.
Freaky how this happened. How big a coincidence to have two people you know with the same phone number just different area codes? I would say it is harder to happen in the USA, but in a small country like New Zealand...
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Comment by xurizaemon, on 12-Nov-2008 20:12
i've seen this several years ago on a nokia also, so it's not just a Phone.exe bug
i believe that in order to match both 09-555-2134 and +6495551234 and 006495551234, the ID matching works from the right side, and will happily match on "close enough"
i suspect you've got enough contacts to make it not such a long shot that two have hugely similar numbers.
i've noticed a few singularities emerging in that cloud myself.
(hmm. "a few singularities"?)
Comment by akia, on 12-Nov-2008 20:34
I haven't heard of it before but that's really interesting.
Comment by manhinli, on 12-Nov-2008 20:35
In a related kind of idea, I've been setting my phone numbers with just plain 123-4567 in my cordless phone. I've got Caller ID, and the phone magically attaches the number to the contact.
Caller IDs come as 09-123-4567, so I've also wondered what will happen when two nearly identical numbers show up...
... now I know! 
(This could really become a common problem only when you've got a huge number of stored contacts really and I don't think it's just WinMo devices too)
Comment by sbiddle, on 12-Nov-2008 21:50
This sort of issue used to exist in the old days with Nokia handsets (I don't know how S60 handles this now). If you had contacts with the same number (ie an 021 and 025/027 number with only the prefix differing) it would just take the one that came first in the alphabet.
Comment by Nick Read, on 12-Nov-2008 21:53
I believe it works this way (and must work this way) to be able to match the number successfully no matter how it is presented, eg:
555 1234
04 555 1234
+644 555 1234
00644 555 1234
0011644 555 1234
All the same number just presented in different circumstances. So it assumes that as long as seven digits are the same (from the right) it is the same number. Of course, whether this is unique depends on the numbering plan of that country. And having the same 7 digits at the end IS kind of a low probability...
Comment by Daveydownsouth, on 13-Nov-2008 10:33
It's always been there in Windows Mobile. WM2003 - WM6.
I notice it because my wifes cell number is the same our home number. I.e... 027 123 4567 and 03 123 4567.
WM has always shown her cell number as the home number. I've never been able to tell which number she's actually calling from.
Comment by jeremy, on 13-Nov-2008 12:36
This could be seen as an interesting example of the birthday problem - http://en.wikipedia.org/wiki/Birthday_paradox. Collisions between rare events are much more likely than you think.
Assuming 7 digit phone numbers, you have a 50% chance of a collision if you have more than 1177 contacts (and numbers are randomly distributed). Care to share how many contacts you have?
Comment by jeremy, on 13-Nov-2008 12:49
Crap, 7 digits have 9999999 not 1000000 possibilities. The 50% number is 3274 or above.
I guess the 1177 number may be closer to the truth, given non-uniform distribution of numbers and numbers like 555 that are not given out. So an unlikely clash, but not amazing.
Comment by Kevin, on 13-Nov-2008 14:20
There's actually a setting to determine the default number of trailing digits used for call ID matches. The default is 8, although it sounds like your device has defaulted to 7.
Might be worth looking into - the easiest way to change it would be the advanced configuration tool at http://www.touchxperience.com/en/advanced-configuration-tool.html
Comment by Jib Bob, on 13-Nov-2008 16:48
You seem to be mistaking "interesting" for very dull. Who really cares about a small glitch with the iPhone.
Comment by Daveydownsouth, on 14-Nov-2008 14:45
Kevin, your a genius!!!!
That worked beautifully. That Advanced Configuration Tool is a great wee program.
Can now differenciate between Home number and my wifes mobile.
Thanks!
Comment by Amit Dunsky, on 17-Nov-2008 10:18
This is a long time bug, which I first come across with in WM5, back in my TyTN days, going thru BlackJack and it continues today with WM6.1 running at my Omnia.
My wife and Daughter's phone numbers differs with a single digit. Every time my daughter phone me, I see her number on the screen, but the name and picture is my wife's.
It is quite an annoying bug.
Amit.
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Comment by Steven, on 12-Nov-2008 19:58
Hi I am also in New Zealand and I have a similar problem. I have a friend with a home number the same as their mobile number and because my Nokia phone thinks I have the same number in my phonebook twice it does not display the caller.
example.
Home number 04 123 4567,
Mobile 021 123 4567