What I meant as far as setting the perl bits in the root environment similar to what is in the zimbra user's, is, as root, run these at the shell on RHEL4:
This should tell perl to use the Zimbra perl libraries before using the system perl libraries.
The root of the problem is that RedHat, for whatever reason, decided to build Scalar::Util without XS support on 32-bit RHEL4. RHEL4 64-bit, RHEL5, and RHEL5 64-bit do not have this issue.
Zimbra :: the leader in open source messaging and collaboration