Adam,
You did not miss much. The conditions you set were such that there are no clusters to be found. At a threshold of 10.99, you get just one cluster that meets your minimum area criterion.
The program would normally tell you that there are no clusters. However, because of the -out_clusterdset, it proceeded to form a dset from an empty list which caused the crash. I should have checked for this condition of course and this bug has now been fixed but your results for this command will not change.
cheers,
ziad