Don't you have to give size when using decimal type:

.Parameters.Append .CreateParameter("@ReturnPercentNumb", adDecimal, adParamOutput,10,4)

>When I run the following code, I get an error message - "The precision is invalid". This must have something to do with the Decimal data type of the second output paramater.
>
>I haven't come across any examples of appending params to a Stored Procedure using the Decimal datatype. Any ideas on what I have to change in order to make this work ...
>
>

>Dim cmdMatched As New ADODB.Command
>    Dim dblTest As Double
>
>    With cmdMatched
>        .ActiveConnection = gobjDataAccess.objConn
>        .CommandType = adCmdStoredProc
>        .CommandText = "up_PercentageMatchedGLTrans"
>        .Parameters.Append .CreateParameter("@ReturnPercentChar", adVarChar, adParamOutput, 20)
>        .Parameters.Append .CreateParameter("@ReturnPercentNumb", adDecimal, adParamOutput)
>    End With
>
>   cmdMatched.Execute
>
>   dblTest = cmdMatched.Parameters("@ReturnPercentNumb")
>
>   Set cmdMatched = Nothing
>
>