Facing problem after adding flv MIME type in iis

Question

Hi,
Am facing one serious problem after adding MIME type (video/x-flv) in IIS. Am adding MIME type to play flv files in flash. Wen i do so session is getting expired and page is getting redirected to login page. If i remove MIME type it works perfectly fine. Am unable to slove this issue.
Plz help me out guys.

Thanks in advance