Issue #1426122 by deletedaccount, Alan D., andypost, maximpodorov: Some callbacks return junk when calling drupal_not_found(); replace with return MENU_NOT_FOUND instead.
Merge pull request #402 from hellomrcat/d7-notfound

Issue #1426122 by deletedaccount, Alan D., andypost, maximpodorov: Some callbacks return junk when calling drupal_not_found(); replace with return MENU_NOT_FOUND instead.