It's a very good script. Please note that you should have same collation in both SQL db's.
Among other problems I had to delete some users with duplicate emails (don't know how was that even possible), also subforums with same name and those having " ' " in their name eg. "developers' corner".
Now I need your help/ideas on this:
Migrating threads and thread posts...
Error executing query: Unknown column 'yes' in 'field list'