The Software doesent have a option to turn the gsm/gprs unit on / off at 10 sec or 30 sec intervall ( aka, using your gps's voice mailbox as a mailbox )?
For me, a gsm needs to be a 100% dial out system ( if i need to ), or a non bother in-system, aka, let people leave message's in the voice mail, and inform me about it with a beep, but the gsm unit doesent need to keep the connection action 100% of the time for me ( to be honest, i'm fed up with people calling at the wrong moments, but i havent seen a gsm unit that can turn itself off & on at intervall's.