Motion Detector recognition

Hi
I'm having trouble installing the motion detectors. I get to add device/motion etc and then it tells me to press the button on top, which I do and then I get the spinning dial but it never recognizes the device!
Maybe Im doing some thing wrong but I just don't see it. Pulled the battery blocker, had it it right next to the key pad.i've even tried the second motion detector and same result
any ideas will be greatly appreciated
Tim