[ODE] Curious behavior with a simple gravity example

[jcwode@nym.hush.com]

My apologies if this question hits the list twice.  My email 
provider seemed to be having some issues last night.

Hi,

I've recently been working with ODE v0.7.  This is my first
experience with ODE, so I'm hoping that what I'm seeing can easily
be explained by someone with more experience than I have.

I've created a simulation, almost like an ODE "Hello World", with a
single World and a single Body.  There is only one force in the
simulation, that being the World's gravity.

Regardless of what step function, running time, or step size that I
use, I always see the same strange behavior.  The body always
overshoots its expected final position.  However, it always
overshoots in a predictable manner.  If I average its final
position and its position prior to the last step, I get the value
that I was looking for (the correct one).  Has anyone seen this
before?

I've written up a similar explanation and posted sample code here:

http://ode.petrucci.ch/viewtopic.php?p=1924

I'm hoping that's it's an error on my part, and that someone here 
has some insight.

Thanks for any suggestions,
Josh