Org-mode HEAD=4b6d270b1615534ef87e330fb2519f4095ea776a, Go id=44699e529c44
Emacs org-mode: http://orgmode.org/

Org-mode with auto-fill-mode is supposed to work like this:

---
################################################
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX try writing past the end of this line:

---
=>

---
################################################
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX try writing past the end of this line:
lorem ipsum
--

However, when go-mode is loaded by opening a .go file in another Emacs
buffer, something goes wrong. Now the result in the org-mode file is this:

---
################################################
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX try writing past the end of this line:

---
=>

---
################################################
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX try writing past the end of this line:
################################################lorem ipsum
--

Org-mode would normally only insert the hash symbol prefix on the line
immediately below the one currently containing the same prefix. After
loading go-mode in another buffer, org mode starts to recognize the hash
symbols from many lines above the current one and automatically adding the
hashes after autofill linebreaks where they do not belong.