Why is that a problem?
That rule tells googlebot and other search crawlers not to crawl files or links in the /nofollow folder
The only way that could be a problem is if you actually have a folder named nofollow. I recommend don't create a folder with that name so you will not have any problem, but if you really need a real folder with that name you could edit your copy of robots.txt to remove that rule.
The purpose of that rule is for when I want to track link clicks in google analytics for external links and other purposes where the page url I want to track for tracking purposes only does not really exist. For example I track click for advertisement links on this site like this:
<a href="http://i7media.net/mojoportal-skinning?utm_source=mojoportal&utm_medium=cpc&utm_campaign=mojoportal" onclick="_gaq.push(['_trackPageview','/nofollow/ad/i7media/i7media-skinning.aspx']);return true;"></a>
Hope that helps,