O.k., I tried it with e-screen and it didn´t work out...

Yes, I have a BB specific data-plan (and so is also the sim). As I wrote in the past, everything works well with another BB-device.

Interestingly some e-screen sections there is shown "EDGE"....but not in the "main screen".

I also tried it with the help desk - they don´t have an idea...
As I said, the device is recognized within BIS...