Strange indentation in message-mode

[Thorsten Jolitz]

Hi List, 
after a lot of emacs configuration tweaking I suddenly have some strange
      formatting issues in message-mode. After the first line in a
      paragraph, all the next lines are automagically indented (without
      me doing anything about it). Just like in this email. 

The mode line says:

,------------------------------------------------
| Message MML AC OrgTbl OrgStruct yas Abbrev Fill
`------------------------------------------------

and I deactivated OrgTbl and then OrgStruct, but the problem did not go
    away. When I deactivate auto-fill-mode, the lines get very long, and
    when I press M-q the paragraphs get filled correctly. But with
    auto-fill-mode activated, M-q does not undo the strange indentation. 

Any idea what could be the problem?

-- 
cheers,
Thorsten