Does it work if you put it in the root folder of your web application?
Does it work if you put the file in a new web site in IIS without ASP.NET or EPiServer?
If yes, compare working and non-workin the request and response using Fiddler2 and post here.
When I upload an eps file using the File Manager, it appears in the file list (with a white/blank icon), but I can't view it or open it. I've checked the IIS mime type settings, and it allows eps files as "application/postsscript".
It's an EPiServer CMS 5 R2.
So what's the problem?