It appears that 3 items are returning 404s and they are hindering page load performance.

http://www.XYZ.com/files/cache/css/simplicity/css/reset.css...
http://www.XYZ.com/files/cache/css/simplicity/css/tooltip.css...
http://www.XYZ.com/files/cache/css/simplicity/css/forms.css...

All return as 404 (not found) after about 900 ms of waiting (each!).

Now, two things are (or could) be the issue here.
1. The content type assigned is "text/html" where it should be "text/css" like all the other CSS files are.
2. They are legitimately missing.

By my estimations, page load time can be reduced from about 4 seconds to under 2 seconds every page.

it appears to happen on every page and I don't know how to change the "default" page.