when use

return grep { s/(\Q$dir\E)(\w+)(\.pm)$/$2/g } %$packlist ;
or
return grep { s/(\Q$dir\E)(\w+?)(\.pm)$/$2/g } %$packlist ;
[download]

gives me the same errors.
I think this problem occures when it encounters something like /usr/lib/perl5/site_perl/5.8.7/My_Package/Sub_Package/Some_Module.pm.swp

Luca