Hi Colm,
Because your mask is so tiny, most of the cluster table entries
are invalid. Then the WARNING_message() function is not
equipped to handle all of the subsequent warnings, at least not
the way it was called.
I can add a little fix for this, but you might consider adding your
own -pthr option for now, e.g.
-pthr 0.02 0.01 0.005 0.001
or whatever else you want in the list.
- rick