Most external themes fail to load .css

pnear

I'm guessing that they simply aren't compatible with the latest version of ZP, but it never hurts to ask. For example, if I try to enable the EnsellitisZen theme the page that loads up is obviously broken. The source that is attempting to read the CSS file states:
<link rel="stylesheet" href="<?= $_zp_themeroot ?>/zen.css" type="text/css" />

Included themes work fine.

Just getting started with ZenPhoto, thanks for the work and thanks in advance for helping with my question.

Pete