I can vouch for the stock perl in RHEL3 being quite broken for things that use threads. Also, RedHat seems to have fiddled with perl's CPAN build tool-kit. Modules that I've never seen fail tests fail spectacularly. Using CPAN to update core modules leads to further hell when up2date clobbers part of the updates when updating perl!
While I've found ways of making all this work, I wouldn't recommend it to any *sane* individual.
My advice to srinivas_rocks
is to try to confirm or rule out ActiveState Perl as your problem as soon as possible, because using it as your system perl on RHEL 3 is *much* better than using RedHat's.
This isn't to say I'm the be-all end-all authority on this, but I consider myself quite a competent and capable sysadmin and never have I been so dismayed with a core system package as I have been with perl on RedHat Enterprise Linux.