Well, hard situation. The new SIM card is sending SMS with location, but the new SIM must have some plan or prepaid services. Off course you can use the portal solution, in case you did pair your device before theft - this service is reachable via internet, so the prepaid services is not a condition in this case. Sadly, in case the thief has been able to flash new ROM, I am afraid no application /incl. LBE/ did survive so the device is lost. Did you try to send any other commands, like siren or wipe? Btw. today is not possible to prevent flashing the device via antitheft. Did you at least receive any message after the theft? Like new IMEI and phone number etc.?