Hmmm... I don't see the bug on my Linux box:

$ cat /etc/redhat-release 
Red Hat Enterprise Linux WS release 4 (Nahant Update 4)

$ perl -v

This is perl, v5.8.5 built for i686-linux-thread-multi

Copyright 1987-2004, Larry Wall

Perl may be copied only under the terms of either the Artistic License
+ or the
GNU General Public License, which may be found in the Perl 5 source ki
+t.

Complete documentation for Perl, including FAQ lists, should be found 
+on
this system using `man perl' or `perldoc perl'.  If you have access to
+ the
Internet, point your browser at http://www.perl.com/, the Perl Home Pa
+ge.
[download]

UPDATE: I was wrong. My use warnings; was commented out. Bug confirmed on my platform.