VERY strange issue with SQL 2000 + ADO Command object

Hi,

I am running into an extremely frustrating problem and after hours of
troubleshooting have not made any progress. When I try to use the ADO
Command object to update a table, I receive the following error message:

Microsoft OLE DB Provider for ODBC Drivers error '80040e10'
No value given for one or more required parameters.


Here is the entirety of the code that is running:

Set Conn = Server.CreateObject("ADODB.Connection")
Conn.Open Application("App_ConnectionString")

Set Cmd = CreateObject("ADODB.Command")
Cmd.ActiveConnection = Conn
Cmd.CommandType = adCmdText
Cmd.Prepared = True

Cmd.CommandText = "UPDATE tblFile SET UserID = ?"

Set var1 = Cmd.CreateParameter("UserID", adInteger, adParamInput)
var1.Value = 1
Cmd.Execute

Set Cmd = Nothing
Conn.Close
Set Conn = Nothing


I use this syntax all over the site with much more complicated queries, and
have never come across this error before. Here is where it gets really
funky..... I've logged var1.Value right before executing the command, and
that is returning the correct value. However the "no value given" error
message persists! If I take the exact same SQL statement and run it from SQL
Management Studio, it runs without a hitch. Additionally if I change the ?
to the value itself, then it also runs no problem.


Now when I comment out the line "Cmd.Prepared = True" then I receive a
slightly different error message:

Microsoft OLE DB Provider for ODBC Drivers error '80040e10'
[Microsoft][ODBC SQL Server Driver]COUNT field incorrect or syntax error


When I run a database trace, I can see that the statement is not actually
run on the server. So this looks to be some kind of driver problem. With
"Cmd.Prepared = True" the only thing run on the server is "SET FMTONLY ON
select UserID from tblFile where 1=2 SET FMTONLY OFF"


I have dropped every DDL dependencies (all two of them) so that should not
be a problem. I can change the CommandText to something crazy like
"UzzzzPDATE tblzzzzFile zzzz SEzzzT UszzzzerID = ?" and still get the same
two error messages. Heck, I've even gone so far as to remove the entire
TABLE from the database and I am *still* getting the same two error messages
complaining that I am missing a parameter. Only when I hardcode the UserID
value in the CommandText does it tell me the table does not exist.

Please help..... Any idea as to what is going on? This is killing me.

Thanks in advance.

Regards,
Mike