On the iTrader feedback form there's a block for "Deal thread URL:". If you cut and paste a URL from the Classifieds, when you submit the form it comes back with "The deal URL is invalid!"
I had the same thing happen on another vBulletin forum not too long ago. When I tried to figure out why it wasn't working, I noticed that below the "Deal thread URL" block it says
However, all the links on the site are now https
://. Apparently the feedback form doesn't recognize https as a valid link, so when you cut and paste the link directly from the Classifieds it won't work. However, if you delete the 's' the link starts with http://,
the feedback goes through just fine.