CreateMHTMLBody With Local ASP URL Doesn't Work

I have an ASP page that I call on my server, say:

http://myserver.com/firstPage.asp

In this first ASP page, I want to send a MIME email that has the
contents of another ASP page which is located on the same server. So
the code looks like:

<%
Set objCdoMesg = Server.CreateObject("CDO.Message")
objCdoMesg.CreateMHTMLBody("http://myserver.com/secondPage.asp")
objCdoMesg.To = "me@mymail.com"
objCdoMesg.From = "me@mymail.com"
objCdoMesg.Subject = "Testing MIME messages"
objCdoMesg.Send
%>

This process will hang on the CreateMHTMLBody() method call. If I
move the second page to another server and reference it there, it's
fine. If I rename the second page to "secondPage.html" and leave it
on the local server and reference it that way (the second page doesn't
have any ASP code in it at this point, just HTML), it's fine.

It seems like the only time the hang occurs is when the requested file
is an ASP page and is located on the local server.

Anyone seen anything like this? I'm running on Windows 2000 Server
with all the current security updates. Seems like it may be something
in the way the process(es) are running.