Business::ISSN - where is is_valid_checksum

[CaMelRyder]

Hi, I've been trying to use Business::ISSN to recognize issns. The problem is that this module doesn't do what it's man page says. Here is an except from the man page :

        #EXPORTABLE FUNCTIONS

         use Business::ISSN qw( is_valid_checksum );

         #verify the checksum
         if( is_valid_checksum(’01234567’) ) { ... }

You can clearly see that is exports is_valid_checksum. However, when I try to use this module like this:

use Business::ISSN qw(is_valid_checksum);

my $issn = '0742-4477';
print "Valid = " . is_valid_checksum($issn);

It bombs out with this:

"is_valid_checksum" is not exported by the Business::ISSN module
Can't continue after import errors at test.pl line 1
BEGIN failed--compilation aborted at test.pl line 1.

Any ideas as to why I can't import this function? Just so you know, the object-oriented way of using this module doesn't work either. Same jazz with finding 'new'. Has anybody seen anything like this before, or is it just a documentation error?