Hi,
Thanks for your reply. This issue exists for all the pages on my zen cart store, not just a few off them.

This is what I get when I use the fetch as a google bot tool on the google webmasters website:

Code:
HTTP/1.1 404 Not Found
Date: Wed, 24 Nov 2010 20:28:13 GMT
Server: Apache
Expires: Thu, 19 Nov 1981 08:52:00 GMT
Cache-Control: no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Pragma: no-cache
Set-Cookie: zenid=sessid; path=/shop; domain=.www.domain.tld; HttpOnly
Vary: Accept-Encoding
Content-Encoding: gzip
Content-Length: 20
Keep-Alive: timeout=15, max=100
Connection: Keep-Alive
Content-Type: text/html; charset=iso-8859-1