I'm an out-of-the-box installer, and don't really understand the ins-and-outs of .htaccess, .php, .sql </disclaimer>
This seemed worth mentioning - not necessarily after a fix (although that would be nice) but considered that it might point to something that may be worth knowing about:
Installed Zenphoto into a /gallery directory of a domain that also includes a Wordpress blog. I noticed that when the zenphoto stuff was in place, the BaStats visitors functionality went ballistic. Every visit to a new page reset all the previous stats to that same page.
Seems to be connected with "running PHP as CGI" option (I use Dreamhost) .. or perhaps the .htaccess file?
Anyway, hope this is useful to someone. For now, I have had to conclude that my existing blog setup (with BaStats) and Zenphoto are not mutually compatible .. but there are ways round that!