Could it be that you were in an area that doesn't have good AT&T coverage? That's what they run off of. I know some of the places I hunt I can't use them because of that. My phones are Verizon and I get great service, but then when in some of the more remote areas where AT&T isn't so good, I don't even bother to set them. It's a pain in the butt, but all of the wireless cams have their ups and downs.