internal server error with new page

Greetings. I’m trying to add an Amazon.com aStore page to my site, http://www.catsignal.com. I think I’ve got the template built correctly because I can see the Amazon stuff as it should appear on preview when I edit the file. I can’t get the page to publish, though. I’m getting an Internal Server Error 500 message. The template is in the folder for the current theme. Perhaps related: Under Page Template, when I go to select the template I want to publish, it says aStore*/?>. Should it have the characters after aStore? Thanks for helping an idiot newbie.