If you've been using a 1.x version of TH-M2C, you will need to make one 
change in your setup to insure proper functioning of version 2.  Go into 
PCBSETUP and verify that there are no spaces in the names of the conferences 
that you will be importing messages to.  For example, if you had a 
conference named:

Mailing List Conference

you could change the name to:

MailingListConference

or

Mailing.List.Conference

or

Mailing-List-Conference

or...  You get the idea.

While you're in PCBSETUP, you might also double-check the second page of 
each conference's configuration and make sure that it really is set as type 
3 (Usenet Moderated).  This is somewhat more important in version 2 than it 
was in version 1.