Here is the article where I read that -- I don't know if it still applies (the article is talking about an older version of CPAN && Perl). I personally had problems installing Bundle::Cpan with CPAN, but perhaps this was due to my own ignorance of how to use it properly -- I just took the lazy route to fix it and did "emerge perl", which fixed cpan for me. Perhaps someone more knowledgable could say whether this article is outdated/untrue/etc...