Duplicate content in google via sort by price/item name

Hi,

I am trying to figure out how to turn off the links for the sort by item name and sort by price.

What is happening is duplicate content which is causing some penalties. These url's are showing the same content just in a different order.

http://ledneonlight.com/index.php?main_page=index&cPath=16_17

http://ledneonlight.com/index.php?main_page=index&cPath=16_17&page=1&sort=2a

http://ledneonlight.com/index.php?main_page=index&cPath=16_17&page=1&sort=3a

http://ledneonlight.com/index.php?main_page=index&cPath=16_17&page=1&sort=2d

http://ledneonlight.com/index.php?main_page=index&cPath=16_17&page=1&sort=3d

I have blocked the sort url's with my robots.txt

Is there a way the sort order can be turned off? Looking at my webstats over the past year hardly anyone even uses the sort options and they do cause pages to be improperly indexed.

Anyone have any ideas?

Check out the link at the bottom from the Google Webmaster site. As far as I have read, there is little to no penalty with this issue when using the ZC and you follow the rules as stated....

http://www.google.com/support/webmasters/bin/static.py?page=ugc.cs&url=http://googlewebmastercentral.##########################/2008/09/demystifying-duplicate-content-penalty.html&signed_url=http://www.google.com/url?q=http://googlewebmastercentral.##########################/2008/09/demystifying-duplicate-content-penalty.html&usg=AFQjCNHhiJfeafis4VyK1GV4lV37lt6r6w