title: Drupal: Cannot save any nodes of certain content types, used to work
body: <p>Whenever I save or create a node of a certain user-defined type, I am back in the edit window instead of switching to the first tab labeled view. All my fields (body, title etc. are as they were and no message appears, neither directly on the page nor in the watchdog database log. The validation is working, though, because I see those 'required' messages as soon as I try to save without Title for example. </p>
  
  <p>The strange thing is that when I create a new content type, or use the predefined story and page types, I can edit and create nodes. In the latter case, Drupal answers with an 302 redirect, whereas with the proplematic content types, only a 200 HTTP status is returned.</p>
  
  <p>The issue doesn't seem to be related to either JavaScript (on or off, no difference), Browser (tried Chrome and Firefox) or WYSIWYG (used input formats with and without).</p>
  
  <p>I'm using Drupal 6.22 and the CCK. I have about 7 content types, some of them with fields. I am not using Rules, but a multitude of modules, all of which are up-to-date. I will post a list if this issue can't be solved otherwise.</p>
  
  <p>I have spend the last hours trying to figure this out, both by looking at my installation (settings, database) and by searching Google &amp; Co.
  Any ideas?</p>