Mine is intermittent, but has happened several times in the 2 weeks I've had mine. Says searching for FOB, and sometimes I have to put it in the slot to get it to recognize. I thought the battery in one might be weak, and changed FOBs. Same thing occurred the next day. I'm going to get two name brand coin cells and see if that makes a difference.

Mine is an iPhone 4 with a hard plastic case that covers the antenna band. I usually put both in the center console...

Best,
Brad