I’m not sure, but this is probably a bug.

I have documents set to be unpublished on certain dates. For some documents this works ok, but others aren’t unpublished. I can’t tell why sometimes it works and sometimes it doesn’t.
In the site schedule all documents with their unpublish dates are mentioned, but some of these are in fact still visible and their names are still orange in the site document tree (on the site schedule page, all names are dark red). However, all dates have passed by now, so none of them should still be published. And yet they are.
I hope anyone can help me with this. I have used the fixes mentioned here:
http://modxcms.com/forums/index.php/topic,4528.0.html, perhaps when fixing something I broke something else?