I think duplicate posts are caused by a couple of minor issues, if you browser "hangs" due to slow internet connection or high internet/sever traffic and you click the submit button again it will duplicate post, and on occasion I have submitted, figured it hasn't gone thru, pasted and reposted only to find a duplicate. I refresh the portal page everytime I view it but it doesn't always reflect the most recent post. Bob you can have all the duplicate checks you want...but by the time you get them the orginals will all have been cashed
Aaron