as I've been quiet for a long time now, here's a little update. Version 0.4.0-25 is now available on the download page in deb-, rpm-, and tar.gz-flavors.
In short, this version should work as well (or not) as the previous version 0.3.3. I just added two more modems which require PDU mode to work. All the rest ist "just" a redesign of the whole thing. That is done and OK, IMHO. All I need now is the motivation to go on with all the other plans I have...
My plans for version 4.1 include getting rid of that modem list for PDU mode modems. I'll simply try a cleartext USSD query first. If that fails, I'll simply repeat the query, this time PDU encoded. I hope that'll work out OK.