I'm trying to start a file download, and everything seems to work fine, except that there is a strange behavior in Internet Explorer. Basically, I'm appending to the HTTP Header to force the file download dialog - it's the one with the following four buttons: Open | Save | Cancel | More Info.

If I choose "Save", everything works fine. I choose the destination for the file and it downloads properly.

Here's the problem:

If I choose "Open", the dialog diappears and then reappears immediately. After clicking "Open" for a second time the document opens properly in a new window. I do not want to allow the document to open in the current browser window - I want to force the download dialog.

Here's the important part of the code:

        Response.Clear()
        Response.ContentType=("Application/pdf")
        Response.AppendHeader("Content-Disposition", "attachment; filename=""" & str_fileName & """")
        Response.WriteFile(fullPath)
        Response.Flush()
        Response.End()