I didn't use any cabs...I just configured mine by creating a new network connection and named it Cingular. Then use wireless.cingular.com and localhost as the proxy, create a new modem associate with this connection with apn= wap.cingular and username WAP@CINGULAR.COM
password CINGULAR1... then just hit the browser with http://device.home
it will connect to cingular's medianet. You can also create a new network connection named it WiFi, leave all settings blank and use this setting for the wireless.
The only interesting thing I found out is that if you have a online account with Cingular..after you logged in, you'll noticed that it automatically detected your HTC tytn phone..even you change it to other type of phone, couple hours..it will detect that you have a HTC tytn. If I put the SIM onto a Motorola K1, it will show unknow phone...interesting.