I can't leave a trader feedback?

I attempted to leave a positive trader feedback for an individual,but it comes back as "Error: (blankspace)".

Whats going on guys?

Jeffhere, send the other guy a private message and have him leave one for you first.
But, do explain the situation you are experiencing now.
You will/should receive a notice of trader rating and should be able to reply with positive rating back.
Rob

One of the mandatory boxes isn't filled?