There seems to be a conflict with the W3TC plugin. Our site uses version 0.9.2.8 of W3TC and 1.1.6 of PS Autositemap. As you can see, our sitemap page is completely jumbled, while the rest of the website displays properly. When I disable W3TC, the sitemap page displays correctly. I've tried both checking and unchecking the "Using cache" sitemap setting, but it's the same either way.