Yep, had that problem last summer. Bears chewed the sensor out of my cam, TWICE. At the time I had the RS PIR mounted outside the case. I have since changed it so that it is mounted flat and haven't had any problems since. I use a metal first aid kit for the case and other than a few scratches it has held up well to the bears. Twisted the devil out of the mounting points and thank goodness for using a chain to attach it to the tree, cause the bungie cords used to hold it tight on the tree were ripped up pretty bad.
But bear tonsils make pretty good pictures, but bear slobbers are a pain to clean off the lens. :smile-big-blue:
It seem that every time I get a bear pic he messes with the camera. I hav'nt had damage to the case or sensor (PVC with sensor mounted inside). other then the switch covers and a lot of slobber. Make sure you clean the lenes before you set it up again.