I've created a small tool to show old versions that are still indexed. It is available here: http://cpanold.chorny.net/ . You can see its output for me http://cpanold.chorny.net/?a=CHORNY . If you have old versions you should delete them (I will do it soon).
Currently there are many distributions that should not be indexed (indexed old versions have problems, for ex. they can be installed over new version without warning). Some authors may not want to delete some version, for ex. it may be last version that they released and after that maintainer changed, or it is the last version that worked on some version of perl. Also CPAN can be reindexed (usually this does not happen). So I propose to create special PAUSE user OLD. Authors will transfer rights for modules that are no longer needed to this user. Comaint will mean that author may reuse this module later and maint will mean that anyone may use this module for his distribution. -- Alexandr Ciornii, http://chorny.net