Mapping Stored Procedure output parameters to To package Variables

I am currently trying to map the output parameters of a stored procedure to variables in a package. However when I run the package I get the following error

Error: 0xC002F210 at SQL_LoadThresholdVariables, Execute SQL Task: Executing the query "EXEC [dbo].[AssignWorkVariables]  ? OUTPUT, ?  OUT..." failed with the following error: "Multiple-step OLE DB operation generated errors. Check each OLE DB status value, if available. No work was done.". Possible failure reasons: Problems with the query, "ResultSet" property not set correctly, parameters not set correctly, or connection not established correctly.

Task failed: SQL_LoadThresholdVariables

My stored procedure definition is as follows:

USE [AutoMatch]
GO
/****** Object:  StoredProcedure [dbo].[AssignWorkVariables]    Script Date: 3/25/2013 2:50:50 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER PROCEDURE [dbo].[AssignWorkVariables]
(
@WT_WEIGHT NUMERIC(3,2) OUTPUT,
@WT_Similarity NUMERIC(3,2) OUTPUT,
@WT_Confidence NUMERIC(3,2) OUTPUT,
@WPerf_WEIGHT NUMERIC(3,2) OUTPUT,
@WPerf_Similarity NUMERIC(3,2) OUTPUT,
@WPerf_Confidence NUMERIC(3,2) OUTPUT
)
AS
SELECT       
 @WT_WEIGHT = MAX(CASE WHEN [FieldName] = 'Title' AND ParameterSetID = 6 THEN [Weight] END), 
 @WT_Similarity = MAX(CASE WHEN [FieldName] = 'Title' AND ParameterSetID = 6 THEN [SimilarityThreshold] END) ,
 @WT_Confidence= MAX(CASE WHEN [FieldName] = 'Title' AND ParameterSetID = 6 THEN [ConfidenceThreshold] END),
 @WPerf_WEIGHT=MAX(CASE WHEN [FieldName] = 'PerformingArtist' AND ParameterSetID = 6 THEN [Weight] END), 
 @WPerf_Similarity=MAX(CASE WHEN [FieldName] = 'PerformingArtist' AND ParameterSetID = 6 THEN [SimilarityThreshold] END),
 @WPerf_Confidence=MAX(CASE WHEN [FieldName] = 'PerformingArtist' AND ParameterSetID = 6 THEN [ConfidenceThreshold] END)
FROM        dbo.Thresholds
WHERE     (ParameterSetID = 6)

In the sql task I have the ResultSet = None

My sql statement is as follows:

EXEC [dbo].[AssignWorkVariables]  ? OUTPUT, ?  OUTPUT, ? OUTPUT,? OUTPUT, ? OUTPUT, ? OUTPUT

I have mapped the parameters using variables defined in the package. This is shown below:

Not sure what I am doing wrong. Any ideas?