OK.... not sure if this will help but lets try
On my Ax5 I have the following setup
Connection Name : Vodafone UK
Modem : Bluetooth Phone or Generic IrDA
Number :*99# <<this activates GPRS on a Nokia, not sure what the seimens code is
User : web
Password : web <<uses Mobile number for authorisation, this info is stored on your mobile
Domand :
**Advanced**
Baud :115200
extra dial-string : +cgdcont=1,"ip","internet",,1,1 <<this is the settings to ensure connection to vodafone UK
Data bits :8
Parity :even
Stop Bits :2
Flow :none
All other settings remain generic.
I got all these settings from the Vodafone web site, allbeit it took some finding but it was there.
Vodafone have a GPRS connection software which includes siemens phones called "ConnectME" you may be able to use this and change the connection settings ???
http://www.vodafone.co.uk/cgi-bin/CO...cegjdgnfdffm.0
hope this helps