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.)