I assume it's the same on both platforms, then? What happens if you set it to "C"?
How about the modules involved? All the same versions? Can you use the same version of Perl, preferably from the same source tree and with build options as similar as possible? This is just the standard troubleshooting checklist that I never resort to unless I can't solve a problem through dumb luck and/or inspiration. 8)
"Even if you are on the right track, you'll get run over if you just sit there." - Will Rogers