Mine did EXACTLY the same thing. I used a couple of dabs of axle grease
in the rear latch mechanism. I poked the stuff way in there with a
small screwdriver, and worked the mechanism a few times. It's been fine
ever since.
If for some reason this doesn't do it, you can still get the thing to
latch: First, you close it until it does latch a little, then pull that
rubber flap up that covers the latch, then use a small screwdriver to
pry the moving part of the latch upwards a bit.
-Simon

On Saturday, September 14, 2002, at 08:43  AM, Mark G wrote:

>  Hello All!  I'm happy to report that the Westy has performed
> admirably on the trip from L.A. to SLC, Utah. except for one thing.
> During the trip, the side door became a bit difficult to close, but it
> was fine after a minute.  However, when we arrived in Utah, the door
> suddenly opened by itself after starting from a stop sign.  SCARY!
> Anything I should check? (I don't want to tell you how my wife and I
> felt after the dozens of times we got out of the front seat to check
> on the young ones on the back. I kept having nightmares of falling out
> of the van and onto the freeway last night.) Anyway, TIA!  On wish us
> luck on the return trip!
>
>
> Mark G.
> 1987 Vanagon Westfalia (to go slow)
> 2000 Passat 1.8T 5SPD(to go fast)
>