setting up gprs properly

[robin]

I am trying to set up my gprs in both shr and qtmoko. unfortunately I do 
not get a data connection with neither of them.
I am using blau.de and according to their website there are either 

APN: internet.eplus.de
Username: blau
Passwort: blau
Authentifizierungstyp: PAP

so I wonder if the authentication might be a problem, as I have not found
a place to set it specifically. 
then they have a specific access if you want to do tethering (I haven't quite
understood how this is different to the first one:

APN/ Zugangspunkt: internet.eplus.de
------------------------------------------------------
Datenträger <- Datadrive: Paketdaten <- Packagedata
------------------------------------------------------
IP-Adresse: dynamisch
------------------------------------------------------
Benutzername: eplus
------------------------------------------------------
Passwort: gprs

but still no success. 

If I set it up with qtmoko I get the little G icon on the homescreen. If I then
click on "start" the icon becomes a filled G for a microsecond, before going
back to the unfilled/unconnected state. Any hints, also how I can investigate 
this?

br

robin