Thread:Project:Support desk/Can't Login due Short-URL

Hello Guys, I installed MediaWiki (1.23) in a Subdomain (http://wiki.prefixaut.net). It's in the wiki-Folder (http://www.prefixaut.net/wiki - Will redirect you to wiki-Subdomain). So after I have struggled for a while to get Short-URLs to work, I can't login. When I click on the Log in button, I get redirected and it tries to show me the index.php Wiki-Page.

To get it working on the Subdomain I tried everything till I REMOVED everything which could cause problems, so the .htaccess file in the /wiki folder is empty and the LocalSettings.php is the default one which MediaWiki generated from the Install.
 * EDIT: In the LocalSettings.php I changed the domain in $wgserver from "$wgServer = "http://www.prefixaut.net";" to "$wgServer = "http://wiki.prefixaut.net";"

I hope you can help me, thanks in advance.