DOCTYPE + Apache + PHP problem

[rgbradley3]

Problem: Shadowbox CSS doesn't appear to apply correctly

If I remove DOCTYPE declaration from the page, Shadowbox works (buncha other CSS stuff gets busted, but Shadowbox works).

.htaccess file contains the following line: AddType application/x-httpd-php .php .html .css

Removing that line, Shadowbox works *with* DOCTYPE declaration.

Any ideas?