no problem for me. I know that felling too well, as I am currently near 
the deadline for my thesis...

That is the reason, why I didn't answer till now. Sorry for that. I 
found the problem. It was a mistake by me. I extended my agents, which 
implement Steppables to MasonGeometries but forgot to add the geometry 
when using them. I had -before I changed them to extend the MG-class - a 
Point-Method which sets and gets the location, but the mason/geomason 
methods work with the getGeometry from the MG - and this i forgot to add 
to my own set-method.
I hope it was understandable what I've tried to say with the sentences 
above ;)

@Sean Luke your post helped me to find my error. Anyway thanks for your 
support, keep up the good work and good luck with the phd!

Am 14.08.2013 03:37, schrieb Mark Coletti:
> On Mon, Aug 12, 2013 at 6:20 PM, Sean Luke <[log in to unmask] 
> <mailto:[log in to unmask]>> wrote:
>     Norman, I am afraid to tell you but our two primary maintainers of
>     GeoMASON (Mark Coletti and Keith Sullivan) are both rushing to
>     finish out their PhDs.  So I'm not sure how soon they'd get back
>     to you on this.  This is clearly a GeoMASON thing and not a MASON
>     thing.
> Sadly I must echo what Sean said: I'm deep in the throes of 
> dissertation crunch mode.  I may have a narrow GeoMASON maintenance 
> window when I turn in a draft sometime within the next couple months 
> where I can address pending problems.
>     So that code should have triggered a NullPointerException *first*.
>      Maybe you've got different code from me and so your line 325
>     isn't what I thought it was?
> Could be he's running from a jar file from an earlier version and not 
> the latest from subversion.
> If anything, I'd urge anyone reading this to prefer using the bleeding 
> edge subversion problem if you encounter GeoMASON problems because a 
> bug fix may have already been committed that repairs your problem. 
>  (And, yes, I need to cut a release, but that's frankly going to have 
> to wait.)