Error when publishing WF containing custom code activity to workflow manager 1.0

Hello:

Workflow manager sounds every exciting to me, I am trying it out to see if it will work for me.

I downloaded "CustomCodeActivitySample" of workflow manager 1.0, and when I ran, I got following exception:

Workflow XAML failed validation due to the following errors:
Cannot create unknown type '{clr-namespace:HashActivity;assembly=HashActivity}ComputeHash'. HTTP headers received from the server - ActivityId: 2a1e4d9d-90bd-4f59-a1fc-d3673194dd54. NodeId: NDL0714. Scope: /CustomCodeActivitiesSample. Client ActivityId : 235d66c1-bbe6-4982-8242-833a6bc1f6b1.

more details:

Microsoft.Workflow.Client.ActivityValidationException was unhandled
  HResult=-2146233088
  Message=Workflow XAML failed validation due to the following errors:
Cannot create unknown type '{clr-namespace:HashActivity;assembly=HashActivity}ComputeHash'. HTTP headers received from the server - ActivityId: efe2c3cb-e6fd-4124-88a1-6c8e72aecb06. NodeId: NDL0714. Scope: /CustomCodeActivitiesSample. Client ActivityId : 73d7b773-be53-4a7b-b2d8-ba687e60a4f4.
  Source=Microsoft.Workflow.Client
  ActivityName=ProcessMovies
  ScopePath=/CustomCodeActivitiesSample
  StackTrace:
       at Microsoft.Workflow.Client.ClientHelpers.SendRequest[T](HttpWebRequest request, T content)
       at Microsoft.Workflow.Client.WorkflowManagementClient.SendRequest[T](HttpWebRequest request, T content)
       at Microsoft.Workflow.Client.ActivityManager.Publish(ActivityDescription description, Boolean overwriteXClassName, Boolean terminateDependentInstances)
       at Microsoft.Workflow.Client.ActivityManager.Publish(ActivityDescription description)
       at Microsoft.Workflow.Samples.Common.WorkflowManagementClientExtensions.PublishWorkflow(WorkflowManagementClient client, String workflowName, String xamlFilePath, Collection`1 externalVariables, IDictionary`2 configValues, SubscriptionFilter activationFilter) in c:\WFM_C\C\Microsoft.Workflow.Samples.Common\WorkflowManagementClientExtensions.cs:line 45
       at Microsoft.Workflow.Samples.Common.WorkflowManagementClientExtensions.PublishWorkflow(WorkflowManagementClient client, String workflowName, String xamlFilePath, SubscriptionFilter activationFilter) in c:\WFM_C\C\Microsoft.Workflow.Samples.Common\WorkflowManagementClientExtensions.cs:line 29
       at CustomCodeActivitySample.Program.Main(String[] args) in c:\WFM_C\C\CustomCodeActivitySample\Program.cs:line 39
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
       at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: System.Net.WebException
       HResult=-2146233079
       Message=The remote server returned an error: (400) Bad Request.
       Source=Microsoft.Workflow.Common
       StackTrace:
            at Microsoft.Workflow.Common.AsyncResult.End[TAsyncResult](IAsyncResult result)
            at Microsoft.Workflow.Client.HttpGetResponseAsyncResult`1.End(IAsyncResult result)
            at Microsoft.Workflow.Client.ClientHelpers.SendRequest[T](HttpWebRequest request, T content)
       InnerException:

Thanks

ahorse