it seems URI-1.18-r1.ebuild doesn't install files at the correct location. all other perl files seem to be stored in /usr/lib/perl5/site_perl/5.6.1/ and, dev-perl/URI installs its files in /usr/lib/site_perl/5.6.1. As a consequence, packages like razor don't emerge anymore.
*** This bug has been marked as a duplicate of 9067 ***