I have tried to edit a suggested edit, which was approved and later edited. My edit came after that and the system rejected its application as is was deemed less substantive. (I applied it from outside the edit queue later, by the way.)
Then I noticed (via Status Watch addon for Firefox) that strange requests are made to the server periodically, failing with 404 status. The
HTTP/1.1 404 Not Found Cache-Control: private Pragma: no-cache Content-Type: text/html; charset=utf-8 X-Frame-Options: SAMEORIGIN Date: Sat, 22 Feb 2014 11:37:44 GMT Content-Length: 26893
I am using unsupported Firefox 17.0.11esr. I cannot test it in a more recent browser now. Still I believe this bug does not depend on most modern features. I’ll be glad if someone could confirm that the requests are made even in supported browser versions.