Can't locate object method connect via package DBI

I am in the midst of a struggle to install Koha on a Red Hat Linux 5.3 system.  I am on the last page of the Fedora INSTALL instructions, and getting the following error:

"Can't locate object method "connect" via package "DBI" in /usr/share/koha/lib/C4/Context.pm line 666"

Here is Context.pm line 666:
my $dbh= DBI->connect("DBI:$db_driver:dbname=$db_name;host=$db_host;port=$db_port",
        $db_user, $db_passwd) or die $DBI::errstr;

I get the same error in two places:
1.  Running zebraqueue_daemon.pl
2.  Trying to connect to Koha using http://localhost/phpmyadmin

I am certain that DBI is installed (although it took a force install in CPAN), that the DBI directory and DBI.pm are in the Perl @INC path, and that the 'use DBI' statement is present in Context.pm.

I am certain that all the variables in line 666 are defined.  I also wrote a very simple perl script to call
DBI->connect and it failed in the same way.

Any help is greatly appreciated.

Thanks,
Sanford Stein