Java Spring Blaze DS - ANTLR Exception

I have a simple java spring server set up that uses hibernate to access the database. However when tring to perform a query on a database table the flex data services wizard testOperation function returns this error message.

InvocationTargetException:There was an error while invoking the operation. Check your server settings and try invoking the operation again. 

Reason: Server error java.lang.NoClassDefFoundError : antlr/ANTLRException null 

now the antlr jar is on the classpath and in the lib folder on the server so i cant see how this is the problem . Does any one have any information on why this error might be occurring. this is the console output also f that helps. I have another class that was created called foo that uses the same hibernate template to save a bar object to the database and this works perfectly. Just when trying to perform actions on the user database.

BlazeDS]FlexSession created with id '0F8814A114349B363B928EDAF0694597' for an Http-based client connection.
[BlazeDS]Deserializing AMF/HTTP request
Version: 3
  (Message #0 targetURI=, responseURI=/0)
    (Array #0)
      [0] = (Typed Object #1 'flex.messaging.messages.RemotingMessage')
        timestamp = 0.0
        headers = (Array #2)
        operation = "findByFname"
        body = (Array #3)
          [0] = "Chris"
        source = null
        remotePassword = null
        remoteUsername = null
        parameters = (Array #4)
          [0] = "Chris"
        messageId = "3E55B425-C80A-FC8F-DE71-1781509D62F8"
        timeToLive = 0.0
        clientId = null
        destination = "userServiceImpl"

2011-01-16 21:27:36 DEBUG [http-8080-2] (SessionImpl.java:247) - opened session at timestamp: 12952132559
[BlazeDS]Serializing AMF/HTTP response
Version: 3
  (Header #0 name=AppendToGatewayUrl, mustUnderstand=true)
    ";jsessionid=0F8814A114349B363B928EDAF0694597"

  (Message #0 targetURI=/0/onStatus, responseURI=)
    (Typed Object #0 'flex.messaging.messages.ErrorMessage')
      headers = (Object #1)
      rootCause = (Typed Object #2 'java.lang.NoClassDefFoundError')
        message = "antlr/ANTLRException"
        localizedMessage = "antlr/ANTLRException"
        cause = (Typed Object #3 'java.lang.ClassNotFoundException')
          message = "antlr.ANTLRException"
          localizedMessage = "antlr.ANTLRException"
          cause = null
          exception = null
      body = null
      correlationId = "3E55B425-C80A-FC8F-DE71-1781509D62F8"
      faultDetail = null
      faultString = "java.lang.NoClassDefFoundError : antlr/ANTLRException"
      clientId = "3E55BD3A-0009-92C7-EA7F-7636A开发者_Python百科529BFBF"
      timeToLive = 0.0
      destination = "userServiceImpl"
      timestamp = 1.295213256298E12
      extendedData = null
      faultCode = "Server.Processing"
      messageId = "3E55C800-CA0B-BE98-FA79-64DC86BD18B1"

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Turns out this is a problem with the new ANTLR jar if you have this problem clean out ur classpath and import the antlr.2.7.6 and see if this solves it . Worked for me