I have 2 products that use the same product layout (the product layout is called "awesome_orange_001_pr_template"). This layout is supposed to show a pop-up link for a larger image ("click to enlarge") underneath the main image on the product page. One product page displays this link but the other product page does not... yet they BOTH use the same product layout. What might the problem be?
Here are the 2 products:
http://www.tullesource.com/white-net-bolt.html (this product has the pop-link).
http://www.tullesource.com/gold-tissue-lame-bolt.html (this product page does not).
Product Layout Does Not Display Properly
Those both look like product more information pages. The more information page is only generated once during a publish (since there can only be one file by a certain name). So if you have the product assigned to multiple pages that used different product templates (Page template can override product specified template) then it is possible that the moreinfo page is being generated by a different product template than you think. So check your page templates to make sure they don't override the product template in the Loop products section.