I have a Lockwood deadlatch that's several years old, predating the digital technology. It has a double cylinder. It was working fine when I moved it to another door. Off the door, everything looks fine--no corrosion or obvious wear, and it works smoothly. On the new door, I can't get it to work. Everything is fine until I tighten the screws (and I'm talking just snug here). Then the latch sticks back. I've probably spent 2 hours fiddling with things to make sure there is no binding or mis-alignment, and lubed the lot with silicone spray. No luck. I suspect something is off just a wee bit, but don't know what to check next. Are these just horribly touchy? Suggestions? (FWIW, this is going on a garden storage shed, so it should be secure enough for this application).
Thanks.