Problem leaving feedback with iTrader?

I have tried several attempts to leave feedback for a member following the instructions as shown but it states that the URL is invalid?

I copied and pasted the URL of the page from the pay it forward thread from which the "deal" had taken place but it will not accept it.
The error message that I am getting is The deal URL is invalid!...any suggestions?

All other options have been completed.

This is the URL that I am trying to reference: I added the arrows at the beginning and end of this so it would show exactly what I have copied ...less the arrows.
<http://www.hkpro.com/forum/hk-parts-accessories-sale/169568-hkpro-pay-forward-thread-15.html>

If I just copy and paste the above address here it shows up like this and you would not be able to see what I have entered.
HKPRO PAY IT FORWARD Thread


Thanks!