If its what im thinking I had this years ago with a Nokia (but not Voda) At
the time the same this used to happen with text messages too
Its a Nokia thing.
Its to do with the +44 - remember to remove the 0
If I added a contact without the +44 in the address book, the NUMBER would
display if they called BUT if I added the contact WITH the +44 their name
would appear when they called.
I would remove your brothers conatct and create a new one for him with
+4479XXXXXXXX
Not sure if storing to phone or
sim makes any difference - maybe just
experiment.
Good Luck