Scalar::Util weaken

Hi all.

I have this minor problem with Scalar::Util. I am using FC4, RT 3.6.x,
Scalar::Util 1.18.

What do I have to do to relieve the following problem? :

error: Undefined subroutine &Scalar::Util::weaken called at
/opt/rt3/lib/RT/Action/Generic.pm line 108.
context:

104: $self->{‘TicketObj’} = $args{‘TicketObj’};
105: $self->{‘TransactionObj’} = $args{‘TransactionObj’};
106: $self->{‘Type’} = $args{‘Type’};
107:
108: Scalar::Util::weaken($self->{‘ScripActionObj’});
109: Scalar::Util::weaken($self->{‘ScripObj’});
110: Scalar::Util::weaken($self->{‘TemplateObj’});
111: Scalar::Util::weaken($self->{‘TicketObj’});
112: Scalar::Util::weaken($self->{‘TransactionObj’});

code stack: /opt/rt3/lib/RT/Action/Generic.pm:108
/opt/rt3/lib/RT/Action/Generic.pm:80
/opt/rt3/share/html/Tools/Offline.html:105
/opt/rt3/share/html/autohandler:279

Thank you.