I am nearing my deadline to bring back the 920 to the store and I am anxiously waiting to see if i can get it unlocked. Until that happens, I did a lot of research and the internet sharing feature seems to break when going to another carrier than Rogers. It seems pretty obvious that this is something baked in the Rogers Rom but no one can "prove it".
Then I found this thread on Nokia's forum
Nokia Support Discussions - Lumia 900 MMS Settings (Where is Network Pofile Ap... - Nokia Support Discussions
It concerns the Lumia 900 but the similarities are too great to ignore, to sum up what I understood from that discussion:
- The normal behavior of the phone is to read the network config (APNs) from the sim card and it sets itself up accordingly. That is the feature rogers allegedly disabled.
- Back then, Nokia released an app called "Network Setup" that would read the config from the sim card and configure the phone correctly. (i.e. it fixes what Rogers broke)
This is obviously a sensitive subject with Nokia. The app in question has been on and off the marketplace (Surprisingly

in Canada) .
I have been talking with a Nokia rep via Email for a few days trying to get to the bottom of this so I can make an informed decision as to whether I unlock and buy the phone or return it. The rep has been evasive to say the least. The last communication I had with him, he suggested that the internet sharing feature is an added "bonus" delivered by the carrier (read: they can take it away if they want to). I wholeheartedly disagree! This is a feature of the phone..period!
I sent him the thread, I guess we'll see where it goes.