title: FileUpload asp.net content type for zip is null
body: <p>I'm using the FileUpload control with .net 3.5 (webforms). Before I accept a file I want to check the content type. And this works just as I want to. The problem I have is that when I try to upload a zip file or a rar file the content type is null and the check fails.</p>
  
  <p>When I debug and check my PostedFile I get the correct ContentLength, FileName and InputStream. But ContentType is null.</p>
  
  <p>Anyone know why I get this problem? All other file types works.</p>
  
  <p>EDIT:</p>
  
  <p>The problem seems to be in chrome only, I get the correct content type in ie and firefox.</p>