Configure IIS to handle vCard

Hi,

I have adopted some old C# (ASP.NET) code that generates a string for VCARD and prints it to the page (Response.Write). On an old server (IIS 6) this works fine, it produces a VCARD-file to download. However, on a newer server (IIS 7.5) the same code only produces the VCARD-string as plain text on the page, it doesn't produce the file to download.

Somebody mentioned to me something about having to configure ISAPI filters in IIS to make this work, but I can't seem to figure out what/where/how :)

Can anyone help me out?

Thanks!