Perl from package perl-5.004m4-1 as installed under Redhat 5.2 doesn't work with Perl/Tk anymore. I had Perl/Tk800.011 (from CPAN) installed and working under 5.1; after upgrading to 5.2 even the simplest Perl/Tk program produces an error referencing an undefined subroutine &main::-1, e.g. perl -MTk -e '$mw=MainWindow->new; $fr = $mw->Frame();' Undefined subroutine &main::-1 called at -e line 1. De-installing and re-installing Perl/Tk doesn't help, switching to a more recent release like Tk800.012 gives exactly the same error. A first work around is to re-install the perl version which was distributed with 5.1. BTW: perl is at 5.005_02 now and 5.004 seems to be rather out of date. And perl 5.005_02 works fine with Tk800.011 on our other, non-Redhat platforms.
We will be updating perl to the latest version with the next release.