I would check with Red Hat and RHN (I assume you really mean RHEL and not CentOS

), but the version of perl that you quote:
perl-5.8.8-2.el4s1
is part of the RHWAS and not the main RHEL-4.
I know of no way it would show up on your system if RHWAS is not enabled. That package is also in CentOSPlus if you are using CentOS.
See who the vendor of that package is with this command:
rpm -qi perl
The Second line should tell you the vendor, something like this:
Code:
Name : perl Relocations: (not relocatable)
Version : 5.8.5 Vendor: CentOS
Release : 36.el4_5.2 Build Date: Wed 07 Nov 2007 03:53:51 PM CST