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Forum Moderators: goodroi
Your robots.tx may impact the pagerank of sites you link to if your robots.txt prevents Google from following your links to other websites. Also if you buy links from someone and that seller uses robots.txt to block Google from following the links to your site, your site's pagerank will not receive the benefit of those paid links.
For detailed discussions about PageRank you should visit the Google Forum [webmasterworld.com]