Using mod_rewrite to prettify MediaWiki URLs as described in the Dreamhost wiki breaks page titles with ? and & characters in the title. There are a number of posts from a MediaWiki developer floating around on the web that claim an alias will avoid this problem:
However, this doesn’t work for me. I get a 500 Internal Server Error.
Alias /wiki /home/mysite/mysite.com/w/index.php