Why is this Visual Studio workflow sending blank task notifications?

Question

We have developed a custom workflow using Visual Studio 2010 in which we are using the CreateTask Activity. For some reason, the first time a task is assigned to a user, the user will receive a notification of the task assigned to them with a blank body. The Subject is correct and the link to the task is correct. Subsequent task notification to the same user are ok. Has anyone else experienced this strange behavior? Any resolutions?

Edit 1

As requested here is the code for the CreateTask activity...

private void createApprovalTask_MethodInvoking(object sender, EventArgs e) 
{ 
    approvalTaskId = Guid.NewGuid(); 
    approvalTaskProperties.AssignedTo = approverUsername; 
    approvalTaskProperties.Description = "Please approve or deny request."; 
    approvalTaskProperties.Title = workflowProperties.Web.Title + " - Request Needs Approval"; 
    approvalTaskProperties.ExtendedProperties["IsComplete"] = false; 
}