[Seam] s:fileUpload Not Working With PhaseEvent Exception

Question

Hi all,

I'm attempting to use a s:fileUpload to upload a file via a Seam app. I've followed the tutorial here but everytime I attempt to perform an upload I get the following exception thrown:

SEVERE: JSF1054: (Phase ID: UPDATE_MODEL_VALUES 4, View ID: /presences.xhtml) Exception thrown during phase execution: javax.faces.event.PhaseEvent[source=com.sun.faces.lifecycle.LifecycleImpl@1d08e21]

I'm having some trouble spotting what I've done wrong. Does anyone have any previous experience with this exception? I can post examples of how I am doing things but it is pretty similar to what is in the link below. I was hoping the exception itself would give somebody a clue to what was going on.

I'm using Seam 2.2.0GA and this is running on Tomcat 6.