OK, the problem has now been resolved.
The reason was no BB service activated for my telephone number. Our lousy secretary could not manage to raise a handset and dictate my number to T-Mobile.
Why was it working for 1 day after registration? I don't know if it's a Mobile Operator-specific bug, but seems that a number of people experience it.
The thing is that it's not Mobile Operator, who controls the BIS service - RIM sends requests to Mobile Operators databases once in two days (according to T-Mobile expert) and if your PIN/IMEI (linked to a sim card during host route table registration procedure) is not in the database of local provider, they (RIM) exclude you from the BIS platform.
That was what happened to me.
Now I'm enjoying the service.
Having read several posts here, I guess quite a number of people experience the same problem (confusion RE BB data plan/service).
Thanks for your support
Originally Posted by aiharkness
Interesting. I don't completely understand, but curious. Post an update when you can.
Posted via BlackBerryForums.com Mobile