I just made two different changes that didn't "stick". One didn't show up on the page after I submitted, but when I went to the edit page and resubmitted, I got an edit conflict, i.e. my previous change showed via the action=edit, but not action=view. Refreshing the edit page and making another, minor change made the first change show up.

Then I made a change to a different page, and it did show up, but disappeared (i.e. silently reverted) a few minutes later, not even showing in history.

(If it matters, the two pages were http://en.wiktionary.org/wiki/Wiktionary:Beer_parlour and http://en.wiktionary.org/wiki/User:Scs.)