Scripting n00b in need of help.

[Cellrage]

I'm going to assume that you have it set so that when you pick up the lantern, it runs "lanterndooractivate".

First thing that you should probably get in the habit of is to add debug messages to whatever functions you're having trouble with so you can visually see if they are being called or not.

On to your script, I can see a few potential problems. One is that the disable auto close should be probably called at the same time as the prop force, as I'm pretty sure the disable auto close isn't permanent.

The second is your actual prop force. The three number inputs stand for x, y, and z, in that order I think. You don't need an impulse in every axis to open the door, only in either the z or the x axis. Check in your level editor to see which direction you should push it, or just experiment with slightly larger values.

Also, I tend to find AddPropImpulse works better for me.