Creating Cookies In Global.asa Session_OnStart But Cannot Read Cookies On Subsequent Pages.

In my Session_OnStart in Global.asa, I am setting some cookies. One
of them, I set as follows:

dim UserID
UserID = Request.ServerVariables("LOGON_USER")
Response.Cookies("User")("ID") = UCASE(UserID)

When I immediately log the cookie value retrieved from
Request.Cookies("User")("ID") into the Windows Event Log, I get the
correct value. However, when I try to retrieve the cookie on the home
page of my application using the same code,

Request.Cookies("User")("ID"), it either cannot find the cookie or
cannot read the value. I am retrieving the cookie before all HTML
headers are written. It is my first statement on the page after
Option Explicit. I have even compared the session IDs. The SessionID
created in the Session_OnStart is the same value as the SessionID on
the home page.

I have read that the Session_OnStart only has access to the
Application, Session and Request objects. It does not explicitly say
that it does not have access to the Response object. Also, I was even
able to use Response.Write's in Global.asa to print out the values
although it looked like it had also stopped the session after I did
so. Cookies are definitely enabled on my machine. I have even tried
setting the session cookie's expiration to be persistent for a few
days to see if it was perhaps expiring before I was able to read it
but this did not work either.

Is there something preventing cookies to be created in Global.asa in
the Session_OnStart sub? Is the Response object not available???
Please let me know if anyone else has had this problem or solution.