Protocol Violation when running Workflow

I’m in the process of setting up AX 2009 and had the Workflow for Purchase Orders working fine with no problems. After working on a customization, not related to workflow at all, and after installing SP1 (I didn’t check workflow right after installation), I now get this error in the event log when I submit a workflow:

Exception thrown in SysWorkflowEventDispatcher-onAcknowledgeWorkflowActivation SysWorkflowEventDispatcher-raiseWorkflowActivationEvent : Web service failed: workflow id WII-000035 The server committed a protocol violation. Section=ResponseHeader Detail=CR must be followed by LF

I’ve looked at the IIS logs, verified the setup, and I’m not able to find the cause of this error. Is there anyone who can point me in the right direction on how to isolate, and hopefully fix, this problem?

This occurs once the workflow is submitted, the workflow goes into the submitted state but it never advances to the first step in the process. Looking at the Workflow History, it stays in the Pending State.

Thanks, Jerry