I purchased Prometheus bundle and successfully watched the film on my PC. I also have a free copy of Dr. Doolittle. Both of these show up on My Movies on my iPad.
However, when I try to go to Vudu.com/movies/ on my browser (Nightly, a version of Firefox) after the first complete playthrough of Prometheus, I get a "Page Not Found" error from the browser for vudu.com/movies/.

My alternative browser, Google Chrome, does display vudu.com/movies/ however. I do not understand what is happening here.