No SIM or Unexpected SIM Status

We have a Airlink LS300 AT&T Gateway that will not recognize the AT&T SIM. The Acemanager 4.0 status tab indicates under network state that there is “No SIM or Unexpected SIM Status”. We have verified the SIM card is active and operational on a AT&T AirCard 815S access point. Any ideas why the SIM card is not being recognized?

Did you find a solution to this? I am having this issue.