Null References on Creating a Task

If you are trying to create a new task in a sharepoint workflow, and it is failing with null reference errors, or "value cannot be null" in the log files, make sure that you are setting the task ID to a valid GUID.

It would appear that just setting the properties to a new field in the workflow designer is not enough, you must have the following line (or similar):

TaskID1 = Guid.NewGuid();

Where TaskID1 is the field that the TaskID has been bound to in the workflow designer.