pcap file showing the problem
I have noticed that if i request the URL http://de.wikinews.org/wiki/Nobelpreis_für_Physik_für_„die_Meister_des_Lichts“ using the text mode browser links, i get a old (outdated) revision of the page.
I have tracked this issue and found that it is caused by links sending the special characters in the URL unencoded, directly as 8bit utf-8, and not in %xy encoding. If i change the URL to use %xy encoding (http://de.wikinews.org/wiki/Nobelpreis_f%C3%BCr_Physik_f%C3%BCr_%E2%80%9Edie_Meister_des_Lichts%E2%80%9C).
However as it seems, mediawiki actually can handle requests with utf-8 in the url, but for some strange reason it returns a old page revision when requesting that way.
I will attach a pcap-trace which shows first a request using links and the a request using lynx (lynx does the %xy encoding). You will notice the different page revisions returned.