I seem to have found a conflict between Network Publisher and WP e-Commerce, and seemingly after upgrading to Network Publisher 3.5.0.
In my WP e-Commerce product pages, when clicking on "Add to Cart" the ajax based "Updating" wheel keeps spinning and hangs. The item does get added to the cart, but without the confirmation message coming to a conclusion. The item can be seen in the cart only after clicking another link, or refreshing the page.
I am by no means an expert, and mainly use Firefox, I am not sure how to use FireBug for debugging, but from what I have tried, all the scripts seem to pass the tests.
Line 119 = eval(returned_data);
Message: Expected ';' wp-e-commerce.js?ver=3.7.58, line 119 character 5
I have de-activated my plugins one by one, and found Network Publisher to be the culprit. When deactivated, "Add to Cart" works fine.
I have spent a lot of time trying to get everything right on my site, and everything worked OK till now...
I am running WordPress 3.0.2., Network Publisher 3.5.0 and WP e-Commerce 3.7.7 without the Gold Cart.
I have only one product in my shop for now, till all runs smoothly, you can see it here: http://www.richardtstrauss.com/fine-art-photography-prints/nature/