I've got cperl-mode.el in /usr/share/emacs/21.3/lisp/progmodes where it belongs (this represents cperl 5.22 from http://math.berkeley.edu/~ilya/software/emacs/cperl-mode.el.5.22.bz2)
Considering the code snippet below: The first '=head1 foo' pod section correctly highlights everything as comments up to and including cut. The second '=head2' pod section is syntax highlighted as if it were code. What's up with that?