Hi,
Our research indicates that this is a problem unique to IE8 - we've contacted our host, incidentally, who said there is nothing that can be done at the server level. We're allowed to alter our .htaccess files and are sure the syntax we used was correct. It did not force a download dialog box for the .vob files in IE8 browsers.
Microsoft offers a couple of workarounds for the problem:
See this page.
We tried adding code in your dfile.php file to send the following to the headers:
X-Content-Type-Options: nosniff
and
X-Download-Options: noopen
However, that had no effect. Let us know if you can think of a better way to try and send these headers... otherwise, I guess we'll just write it off as an IE8 bug.
Vicki