I'm tearing my hair out and quickly going bald trying to solve this problem.
I want to install mediawiki as a subdirectory under my wordpress install with short urls.
viz http://www.example.com <- wordpress here, top level
http://www.example.com/wiki/ <- mediawiki here
mediawiki pages are re-written so that they are short
http://www.example.com/wiki/mypage
I've tried many combinations of editing localsettings.php in mediawiki directory, and .htaccess in wordpress directory, and .htaccess in mediawiki directory with no joy.
I can achieve what I want by running mediawiki from the top of a domain or sub-domain viz
my.example.com/mypage <- mediawiki pages rewritten to short url here
help appreciated. i don't have many strand of hair left ! :-)