I don't post many bargains (long time listener, first time caller) but tried one tonight with the Breville Barista Express machine:
https://www.ozbargain.com.au/node/478854
It would not let me submit as it said it is the same URL from this deal of 2 months ago which is expired:
https://www.ozbargain.com.au/node/465781
I got around it by adding a slash to the URL but I am wondering why it would block a submission of a deal based on an old, expired deal? Does this only every mean one deal per URL? Is this by design? It didn't give me a "not duplicate" confirmation, just said that it already existed.
The 'Not Duplicate' checkbox is there, just a bit further down below the coupon code box: