Anyone heard of this? Weird File Download Problem

We have a Flash website that, among other things, allows users to download files. For 90-95% of users this seems to work just fine, but 5-10% of our users cannot download the files.

What happens: The save file dialog box comes up, the user chooses a location to save to and hits save. The save file dialog closes, and nothing else opens.

The problem, if it occurs on a machine, occurs regardless of the browser the user is using.

We’re trying to figure it out, but it’s very strange and I thought I’d see if anyone had experienced anything similar.