Thanks, Stephen.  

Your response anticipated my next question, which would be the possibility of some sort of cluster threshold.  As you have already figured out, the results from the script allow for even the tiniest clusters.  I wonder if there's a way to just have the results thresholded for an arbitrary cluster (k) size?  While not empirically pleasing, one could reasonably set the cluster extent to a level that would preclude most of the likely noise effects.

Also, did you or your group figure out how to run single-subject ROI-to-ROI, rather than the seed-to-voxel approach?  Seems like this too might aid in diminishing the effect of the very tiny cluster effects.

Warm regards,
Jeff