re:  The solution was simple:  Spray a liberal amount of WD-40 on the
latching mechanism.

Isn't WD-40 so often the solution?  Since it's technically Thursday
and not yet Friday, I still can't resist offering my favorite URL
describing WD-40.  It's wierd but informative.
http://www.forbes.com/forbes/99/0308/6305076a.htm