This is a bit complicated. So I was using a curve 8520 till 2 weeks ago on India's Airtel network, it was working perfectly. THen I bought a new bold 9700

and I changed my device on airtel.blackberry.com . I even confirmed it with airtel bb support.
Now my cousin is in Nigeria and is trying to use this 8520 curve with MTN BB services. He is able to use BBM, browser and everything.
But he is unable to register to BB email by clicking on BB email setup or via mtn.blackberry.com ...... Mind you I wiped the device before giving it to him. But for some reason my old username (airtel bb username is on the device) and when he clicks "forgot password" from his device using MTN in Nigeria I get the password here on my bold 9700 using Airtel in India.
Again, his bbm and gtalk and browser is working BUT he is not able to set up email right now. He is using "yahoo mobile" as of now for email.
When i try to create an account on mtn bb website I get this error:
"The page at bis.eu.blackberry says:
Cannot create account:
This BlackBerry(R) device is not registered with your wireless service provider.
Please register this device and verify that the URL of the current web site matches
the one provided by your wireless service provider.
To register:
1. In the Application list on your device, click Options, or click Settings Options.
2. Click Advanced Options > Host Routing Table.
3. Click the Menu key and click Register Now.
If the error persists, contact your wireless service provider."
I tried that but its still troubleshooting.
HELP!!