The ICCID is written on the outside of the Dualcom GPRS, stored in the EEPROM, read in from the GRPS modem, and read in from EEPROM immediately before a long, random looking, string is sent to a remote server. It seems quite important.
The Dualcom board also frequently checks for received SMS.
It might be worth taking a look at the SIM to see what is on it.
From previous projects, I have an Omnikey Cardman 5321 card reader. This reads both RFID cards and smart cards. We can put the SIM card in a carrier and read it with this device.
SimSpy II is a free utility which can read most data from SIM cards inclouding ICCID, IMSI, Kc (which can be used to decrypt communications), SMS messages and more.
Unfortunately, nothing too interesting comes up. The card never seems to have stored any SMS. There’s no numbers in the phone book. We might end up coming back to this at some point.