Oddly I added :

require base;
base->import(qw(Admin::Base));
use Data::Dumper;

our @ISA;

warn Dumper \@ISA;

And afer touching Test.pm I see Test.pm ISA Admin::Base:

Wed Feb 17 02:46:35 2010 Test.pm: Subroutine pre_dispatch redefined at Test.pm line 15.
Wed Feb 17 02:46:35 2010 Test.pm: Subroutine save_form redefined at Test.pm line 27.
Wed Feb 17 02:46:35 2010 Test.pm: Subroutine form redefined at Test.pm line 93.
Wed Feb 17 02:46:35 2010 Test.pm: $VAR1 = [
Wed Feb 17 02:46:35 2010 Test.pm:           'Admin::Base'
Wed Feb 17 02:46:35 2010 Test.pm:         ];