mhonarc 2.1 - not creating threads.html

Using mhonarc 2.1 under Win95, it creates the msg HTMLs and the maillist.html
but hangs when creating the threads.html.  Any ideas?  The other files are
all created correctly...

Cheers
Robert McArthur

PS. In case it helps with Win95 directory sizes, there are 1770 messages in the
directory...