Please help

Not sure how to describe my problem really, but here goes.

Generally if an incorrect URL is typed in the address bar of IE or any browser, what comes back is either a 404 error or a customer error page.

If an incorrect URL is enetered with http://mooviecows.com/ as the main part of the address, instead of the 404 error or what ever, what comes back is screen full of page source code. Check it out for yourself, just put anything you like after the .com/ and see what you get.

I think the generated code is code that generates the Sidebar and widgets because if I remove the sidebar.php code from the Theme ( Pixelated 1.2) then instead of a page full of code I just get a blank page, which is better but then I have no sidebar. I’m at a loss as what to do to fully correct the issue.

Any help or ideas would be appreciated.