http://www.diy-hq.net/water-heaters-15.html and http://www.diy-hq.net/water-heaters-10.html and

the real/correct URL http://www.diy-hq.net/water-heaters/hot-water-heater-problems-that-you-can-fix.html all point to same content.

I invesitaged by looking at the ARTIO SEF url for water-heaters-10.html and the non-seo is index.php?option=com_content&catid=37&comment_id=179&id=99-hot-water-heater-problems-that-you-can-fix&joscclean=1&view=article&Itemid=42

http://www.diy-hq.net/index.php?option=com_content&catid=37&comment_id=179&id=99-hot-water-heater-problems-that-you-can-fix&joscclean=1&view=article&Itemid=42 is that in FULL URL form and it doesn't jump to the comment either..

We only have this duplicate content problem created by pages with comments left at one point or another.

Any help is appreciated!

Glenn