Attachment_fu validation error

I’ve installed attachment_fu and when I try and upload a file, I get
this validation error:

There were problems with the following fields:

Size is not included in the list

I’ve changed the model to say: :max_size => 2.megabytes, but I still get
the message. My test file is 721 kb. To keep thing simple, I’m testing
with an image file.

I’m will be using attachment_fu to upload documents, so I don’t need
thumbnails and resizing, correct?