I have no dual sim but please read
http://www.windowsphone.com/en-us/ho...dual-sim-phone For single SIM the network name is automatically set in the phone. If you have 2 sim cards and the name was also set automatically you could end up with 2 tiles with the same name
(same provider) To prevent this I think you have to manual name them . Maybe if you only use 1 SIM you can switch of the other and than the nam is automatically set in the tile. (should at least be "technically" possible.
Could this be it?