Situation: the updater may be used to access updates through a proxy server.

Experienced: proxies could serve an outdated copy of the update information file (and others).

Expected: client should always receive an up-to-date copy.

See also: this thread (http://forums.spybot.info/showthread.php?t=12638); next to telling the client to never receive cached files, it might be better to check the expiry date the server delivers on documents.