I wonder... is this tied to the door rust problem that a lot of guys have seen? I know thier solution is to drill a couple of small drainage holes in the bottom of the door so that water doesn't sit inside the door.

Until you find where the water is getting in, you may want to drill a small drain hole, that should at least keep it from filling up and drowning your lock mechanism.

Here's a link to the door rust thread so you can see if it's a similar problem.

https://www.crossfireforum.org/forum...ad.php?t=13449