Internet Explorer not recognizing XML

Hi, yesterday I noticed internet explorer stopped recognizing XML, it just opens a blank page, even pages using XSLT. I noticed it when I started having trouble adding a web service using VS.NET. When I got to a url.com/file.ext?wsdl it attempts to download "file.ext" instead of showing the xml for the wsdl. I'm guessing this is a MIME recognition problem. I'm using vista x64, would anybody know how to solve this?