Is there any way to upgrade the firmware on the M1306B such that it will work with the GSM networks in the USA that use frequencies GSM 850 and GSM 1900?
Ask your Distributor, but I think this is a hardware issue - not just a firmware update?
I got a firm answer that its not possible. USA Frequencies are not supported by this hardware.
M1306B does not support US GSM/GPRS frequencies.
A good alternative is the Maestro Wireless M100
I buy some from there: adm21.fr/index.asp?ID=467&IDF=98