File Download problem in IE7

Hi,
In IE7 When i m trying to a file from our application a file download
window comes up with find, save , cancel buttons with no file
extension present and also filename is not generated. As per our
application the file name should be unique, which is auto generated
(name generation is done by the IE6 browser )and the extension is .sbx
(.sbx is given in our application itself.)When i click on find button
another windows opens up.. showing the below message. and this
application works fine in case of IE6.This problem occurs only in IE7.
Any pointers plz


following msg comes up in another window when i click on Find button
(in IE7)

Windows has the following information about this MIME type. This page
will help you find software needed to open your file.



MIME Type: text/silverback-export

Description: UnKnown

Windows does not recognize this MIME type.

You can search the following Web site for related software and
information:
Windows Live Search