MailBox install problems

Hi,

I am trying to install the Mail::Box perl module on a RedHat  
Enterprise system. During the installation (with CPAN) the  
installation fails. The installation seems to fail on the dependency  
modules: Object::Realize::Later and User::Identity.
During the make test, I get the following errors:

#     Tried to use 'User::Identity'.
#     Error:  Weak references are not implemented in the version of  
perl at /root/.cpan/build/User-Identity-0.90/blib/lib/User/Identity/ 
Item.pm line 8

The same errors occur with Object::Realize::Later.

Im am working with the perl version: perl-5.8.0-89.10

I googled and looked in te mailing archives but found no answer to my  
problem. So can anyone help me?

kind regards,

Matthijs