From that thread:
[quote]if anyone hasnt concluded this post, i happen to run PHP as CGI and this was my fix --> Php.ini
cgi.fix_pathinfo= 1 & cgi.force_redirect = 1[/quote]
But, can php.ini be accessed? I asked about this earlier and got no responses.
It is true that Gallery will not work at Dreamhost unless you run PHP as CGI. The new patches I referred to; 2.9 also take care of the [SCRIPT_NAME] issues. So, you can use those patches and run your site as PHP-CGI.