I'm using a Sony Vaio TZ31WN/B with the supplied T-Mobile SIM card and am finding what apears to be a compatibility issue with T-Mobile's 2G Network viz GPRS (and EDGE for that matter).
Running Vista with Sony supplied driver for the Globetrotter.
When in 3G coverage all works fine. When outside it, but within good 2G coverage, the built in Globetrotter GTM378 module refuses to attach to the 2G network most of the time. It can see it (shows up in network list) but it won't attach. Very rarely it will attach to the 2G network but when it does as soon as a connection is made there's a remote party disconnect.
This happens with both Globetrotter Connect and the T-Mobile Web and Walk Manager (latest version).
If I put a Voda 2G sim in the TZ31 it attaches and connects no problem.
If I put a Novatel Express card in the TZ31, with the T-Mobile SIM in it, it attaches to the T-Mobile 2G network and establishes a GPRS connection instantly and without problems.
All settings (APN, user, password, network settings etc) are identical when used with the Express card and with the built in Globetrotter.
The built in module just won't play with the T-Mobile 2G network (or perhaps it's 1800MHz networks). I checked the band selection of the card and it's correct.
Any ideas?
