enigma1 - 9:19 am on Jun 16, 2010 (gmt 0)
Unless some of the popular spiders don't rectify their algos to identify authoritative sites for specific content, you will see this problem.
You can get around it, but it will be very expensive (initially at least), as you need to ban the spider who doesn't bring you to the top results for original content. And get around the scrap bots of course either feed them with low value content or ban them.
Your content will still be distributed to spiders who do recognize you as the author.