Unable to load gadget content with no authentication

Unable to load gadget content with no authentication

I want to rewrite part of my website exclusively using Google
technologies. (google site, google gadget, google code, google docs, ...)
So I started from the home page where I want to insert two gadgets that
I've developed : https://sites.google.com/a/rapazp.ch/trial/
The first gadget embed a google map with data from a published google
spreadsheet. To write this gadget I was inspired from the following sample
http://goo.gl/dsxrf3. My gadget create a new google map then load the
various markers from a json object obtained by the mean of a shared google
spreadsheet.
The second gadget just retrieve a html representation of a google
spreadsheet.
Overall everything works more or less as I desire. My problem is once I
share the page (and all google spreadsheets) public on the web, the
contents of gadgets do not load if the user is not authenticated.
Is there a way to bypass this authentication or ask the user to
authenticate when it come to the main page ?
Is there another way to load all the page content without authentication ?
Any help would be greatly appreciated.
Pascal