Recently we updated the firmware on a GSM modem and found that it wouldn't work after the upgrade.We discovered that the unit was locking on to the new Telecom network, which meant that the unit decided it must be in a region with 850/1900 networks (instead of 900/1800). So despite having a Vodafone SIM card in the modem, we never got registered on the Vodafone network - at least not until we went in and switched off Autoband select and manually set it to 900/1800.
Can anyone tell me if there are other locations in the world that have both 850 and 900 networks?Reason I ask is that I'd like to do some more testing, particularly to see if we've got potential issues in major markets.
Any suggestions gratefully received.
Nigel H.



