I recently posted an answer on stackoverflow that rendered perfectly in the editor preview, but in the posted text the links all got gobbled up: links were stretching across multiple lines where they shouldn't, from another the url showed up directly in the posting. A friendly fellow on SO then simply replaced the offending url with one that provides the same text on another server, and the problem was gone. The offending url was
http://web.archive.org/web/20070502155005/http://wagerlabs.com/2006/8/25/writing-low-pain-massively-scalable-multiplayer-servers
To see the posting in question check this answer, look for the initial version of it.