The dreaded ADO.Net...

[SjR]

Dim drLibraries As SqlDataReader
Me.cmdSelectLibraries.Parameters("@AddressCode").Value = Me.AddressCode
Me.connBCMS.Open()
drLibraries = cmdSelectLibraries.ExecuteReader

I keep thinking I've got to grips with ADO.Net... but then this keeps bloomin' happening.

Error on the last line shown above... "System Error"

Me.cmdSelectLibraries is a SQLCommand Object (with correctly functioning connection object - tested )
Me.connBCMS is the very same fully functional connection object.
The command text is:
"SELECT * FROM MemberOfList WHERE (AddressCode = @AddressCode)"
Me.AddressCode property is set to a valid value (ie. 3)
The datatype of the parameter is set to Int.

Something very basic missing, and I keep making this mistake.
Anyone spot it?