I haven't driven mine in a few months so I can't remember for sure how
it works but I can get mine open even with the broken spring.  I 
pulled mine apart and found the offending spring and removed it and 
put the whole thing back together.  I think what I do when I want to 
open it is to turn the key to the lock position and then to the open 
position.  If a person unlocks it from inside it screws it up again 
and then I have to 'reset' it by locking it from the outside with the 
key.  I mean, when they do this the key will do nothing.  Also, I can 
just lock it and shut the door normally.  Let me know if you can 
across a source for new springs.  I'd buy one or two.  Jim
-- 
James A. Brill Jr.         \\  //
jbrill@unlinfo.unl.edu   \\ \\// //      If you're not outraged
University of Nebraska    \\//\\//     you're not paying attention.
free-lance homo sapien     \/  \/