After using Zend_GData to retrieve a document list feed, I can use the content URLs in the form:

http://docs.google.com/document/edit?id=<docid>&hl=en

but the source URLs in the form

http://docs.google.com/feeds/download/documents/Export?docId=<docid>&exportFormat=html

are returning 404 errors. That URL should return the content of the document in the requested format but it is returning 404.

This problem is mentioned without resolution on a Google API forum. As indicated in that forum post, this problem only seems to affect new documents. My code works perfectly retrieving old documents, but new ones are 404.

Has something changed in the way Google references new documents or in the way permissions are assigned?

The code I'm using is essentially the same as the code on this page but this does not seem to be an issue specific to PHP/Zend_Gdata.