Layout changed magically overnight!

[kelley777]

(V 1.5.1, manual install, php version 5.3.24 zend: 2.3.0, mysql client api version 5.5.19)
Okay, so I did a manual installation yesterday and have not made any changes, and have not installed any plug-ns or add-ons, except installing the cherry zen template AFTER the problem happened.
Yesterday after installing zencart, there was no apparent problem - the content was centered on the webpages and everything else seemed fine. I did no edits at all. This morning, however, all the content has moved to the left side of the webpage, with only text links at the top. I re-uploaded the original css files straight out of the zencart package, with no result. (I have, since this morning, uploaded the cherry zen or zen cherry, whichever it is, template and switched to that for the default.)
Does anyone have any idea what could have happened? URL: http://kelleywebdesign.com/print/
Thanks, K