Docs Viewer/Cannot See Document/Omeka 2.0

Hello,
I downloaded the Google Docs Viewer plugin described at http://omeka.org/codex/Plugins/DocsViewer_2.0

I configured the Docs viewer and got the message “Sorry, we were unable to find the document at the original source. Verify that the document still exists. “ I changed the pixel dimensions on the configuration page but did not get to view my document. My files have been uploaded and are in the system.

Any ideas?