The case of the disappearing relationship

I am but a novice pushing my envelope of expertise, any help will be gratefully accepted.

I am using a series of Global fields to control access to a separate data file containing images. I also have a separate customer database containing valid user IDs. I was hoping to provide access to the images via another "Viewer" database that contains no actual data but uses information extracted from the function Get(AccountName) assigned to a global field that is linked to the customer database, this relationship allows the Customer's Account Number to be assigned to another global field that in turn provides a link to the image database. Using a series of single instance portals, a sheet of thumbnail images that match the Account Number are then presented to the user in a 4x4 matrix via the "Viewer" database..

What is the problem?

This model works fine from within FileMaker and readily identifies the different customers IDs when I login and displays the relevant images in the desired format. However, when I try to publish the database using the Instant Web Publishing function, none of the relationships seem to work. Am I missing something really basic here?

Regards

Brett