Converting to ADO, Recordset Problem

I am converting a program to ADO, and have worked out most of the bugs, except the sql query I was using to get a listview is not working now. I was using this code to open a recordset:

Set rsListData = dbPrimary.OpenRecordset( _
"SELECT * FROM qryListCustomers WHERE LastName LIKE '" & txtFind.Text & "*" & "'", _
dbOpenDynaset)

And getting:

Run-time error '3001':

Arguments are of the wrong type, are out of acceptable range, or are in conflict with one another.

Since this is ADODB I changed the code to:

Set cmdCustomers = New ADODB.Command
cmdCustomers.CommandText = "SELECT * FROM qryListCustomers WHERE LastName LIKE '" & txtFind.Text & "*" & "'"
cmdCustomers.CommandType = adCmdText

Set paramCustomerID = _
cmdCustomers.CreateParameter("paramCustomerID")
paramCustomerID.Type = adInteger
paramCustomerID.Direction = adParamInput
paramCustomerID.Value = 10
cmdCustomers.Parameters.Append paramCustomerID

Set rsListData = New ADODB.Recordset
rsListData.Open cmdCustomers

But now I am getting:

Run-time error '3079':

Operation is not allowed on an object referencing a closed or invalid connection.

The error is occurring at rsListData.Open cmdCustomers
I believe my connection is open. The code I am using for it is:

dbCust.CursorLocation = adUseClient
dbCust.Open "Provider=Microsoft.Jet.OLEDB.3.51;" _
& "Data Source=C:\My Documents\VBasic\IllustrationADO\Customers\Customers2000.mdb;"

Which is the database holding the tables and query. Any ideas?