I created a template in CS4 and some how the template is no longer centered on the screen rather positions in the upper left corner. How can I center the page.
You have asked a question that it's not possible to answer without seeing your code. There is nothing inherent in templates that causes pages to align to the left. I have a sneaky suspicion that it's something in your code. Can you post a link to the live page, or paste its code into a reply here?
If this template was centered originally, I'm guessing that you have unbalanced <div> </div> tags somewhere in your markup.
Validate code and fix reported errors.
If that doesn't help you, please post the URL to your page.