setting cutoff in mgcluster

setting cutoff in the mgcluster command, i.e. to 0.5, does not work using version 1.33.2. Clustering ends at cutoffs unique or runs until 0.06. Seems to be rather random.

It runs perfectly fine when keeping the default (0.7).

command used

mgcluster(blast=myfile, cutoff=0.5)

It’s the same as with the basic cluster command…

http://www.mothur.org/wiki/Frequently_asked_questions#Why_does_the_cutoff_change_when_I_cluster_with_average_neighbor.3F

This does not explain when the cutoff is set to 0.7 or 0.6 it will end at different cutoffs in one case at 0.06 and in the other at 0.29. Or am I getting something wrong.