Files are corrupt on download

All files that I download with the filevista control are corrupt after download.  They upload fine and are readable on the server but unreadable after download.  I have checked permissions on the folders and everything looks fine there are not folder or file restrictions.

Any idea what I should check next?

I think I figured it out.  I reinstalled the service pack for .net 3.5 framework and it seems to be fine.