Well, you seem to have run in a problem I have as well. Some of the API calls that are defined in the headers are not actually included in the Firmware blob. So you get the -103 code back.
As for why the congstar sim does not work - No idea, but I have an expired congstar sim that i just cut it down to nano-sim and put in the rephone module - the example arduino checksim sketch shows 1 for an active working sim.