Problems getting file upload to work on rails 2.0.2

Hey Guys,

I'm trying to upload a file to rails. I thought it would be pretty
straightforward but I've run into a peculiar bug... the form I'm using
is shown below and then the error message.... any suggestions or
diagnostic hints would be appreciated. I'm running rails 2.0.2 and ruby

<form method="post" enctype="multipart/form-data" action="/page_assets">
    <label for="mugshot">Upload A Mugshot:</label>
    <input type="file" size="30" name="mugshot[uploaded_data]"
    <input type="submit" value="Create" name="commit"/>


Ignore this post.... late night.