Last modified: 2007-12-16 20:20:52 UTC
When viewing an old revision that does not belong to the page with the title specified in the URL, or when no title has been provided (in which case the Main Page is assumed), the user interface links for article, discussion, etc. point to the URL-specified title instead of the page to which the revision belongs. This causes trouble when visiting URLs where only "oldid" is provided.
This is more than just viewing. It also affects protection status, and probably other things as well. Look at <http://en.wikipedia.org/w/index.php?action=edit&oldid=58789934>. Obviously no one should be linking to these in the first place, but someone should still look at it sometime.
*** Bug 9572 has been marked as a duplicate of this bug. ***
This was fixed some time ago by Brion.