When you try to connect, make sure that the following conditions are satisfied.
First of all check that your device is supported by GPS-server in the list of supported devices;
Check that your SIM has sufficient credit/balance and that the SIM is enabled and activated for GPRS. Test this by putting the SIM into a cell phone and browse some web sites over GPRS. (Note that some operators require you to call them to activate the SIM for GPRS);
Make sure that the PIN code on the SIM is deactivated;
Check in object list that the device IMEI is correct;
Check that you are using the correct APN. Ask your operator what APN to use with your SIM. Operators sometimes change an APN;
Check if there is a username/password needed for the APN;
Wait for the device to get a satellite fix, this can take some time (and is best achieved outdoors with clear sky);
Check that the device has a network connection (GPRS status is indicated on most GPS devices).
