Only other things we have seen cause this is if you are any further than about 10 yards from what you want totake a pic of it doesn't work very well. Also if you have it facing the sun, it will take a lot longer to trigger because there is less temp difference to the sensor. We always try to put our in a very shaded area.

Other than that , I don't know.

i bought the stealth three weeks ago,read the instructions,put it on a tree and checked it every 4-5 days.it is set to take two pics each time.it had two pics showing after two weeks.i saw big tracks heading towards the cam but no additional pics,so i put it on test and moved a couple of trees and got the green light.i turned to standby and strapped it down,switched to on and it flashed.i waited 7-8 minutes then walked in front of it and it took two pics.i hope it is working before the batteries go dead.this is not a high traffic area,but i know deer cross here all the time.