I am having the exact same problem. I have added a template to my style called "products", added a file called products.php in the /forums folder, and then changed the file to reference "products" and I just get a blank page.
3.8.0 here...
--------------- Added [DATE]1232408213[/DATE] at [TIME]1232408213[/TIME] ---------------
Problem solved:
I was using an UPPER CASE template name in my php file. Once I changed it to lower-case, which matches the name of the template in the Styles admin it worked.