When I first set up and installed, I was having issues connecting to web, it looked like DNS issues (I did notice Skype connected, but no web/email). I manually configured the connection to use my ISP DNS servers, and bam, worked like a charm. I did have to reboot once, as I had difficulty disabling other adapters. After doing that, I removed the manual DNS entries and no problems from there. With a 2 to 3 bar connection in 2G territory, experienced 69 to 79 Kb down, 46 to 59 Kb up.
My suggestion is to strongly recommend or require that users reboot both devices after installing. I know I hate to do this due to reboot time, but with something like a network adapter install it is probably almost mandatory, and it would make your support much easier. The instructions I received didn't mention rebooting (obvious to many but not all). Also, after that I didn't have to disable other connections, only disconnect. This is a big time savings and much easier for the average user, so if you can recommend disconnect rather than disable I'd strongly suggest you do so.
For the record:
Blackberry 9000 Bold, .167 OS, AT&T (wap.cingular)