I just installed Product Type Book, and while I can log into the admin fine, the catalogue has gone haywire.

this is my error msg:
http://www.mysitename.com/zc_install/index.php

Finding it all abit odd, that it was working, then not working.
Zen is installed and admin area is working fine.
Tried classic template, no joy
Tried future zen template, no joy

Am running Zen 1.3

where to start looking?