MDA I has lost Telefon after update on WM2003

Hallo,

i have an old MDA, and I have decided to upgrade it on WM2003. I have downloaded an oficial Update from Telekom Web page and have successfuly (= without Error Messages) installed it. Then, i have found, that Telefon in MDA doesn't work. There is an Icon of Antenne with a "!" sign and Diagnostic "No Service" ("Kein Dienst" in German), Telefon settings also can not be opened.
Bootloader shows, that GSM OK, does all of the Tests successfully.
I have tried to make the same Update with OSImageTool, but with same result.

Is there any tool, to diagnose, why it does not work???

WHAT CAN I DO???

I have tried to install an older System (3.19). Tha same effect, but also doesn't work ActiveSync. After installing a newer System, ActiveSync has worked, but Telefon is again unusable.

HEEEEELP!!!!!

It is PW10A2.

The numbers on boot screen are...
Now: 4.01.19 R.3.23.00 G32S54

Update:
I have Radio on 3.23.11 updated (still not working)

AAAAAAAAAAAAAAAAAAAAAAA!!!!!!!!!!!!!!!!!!!!!!!

It WORKS!!! In Bootloader menu i have called "GSM 900/1800" and "GSM ON", now Telefon works! I had a super weekend!!!!

No, the only thing I have done, I have installed an Update from Telekom webpage (t-mobile.de/mda/software)... Later I have installed also only German versions. Though, I had no Idea, that Band could be changed.