Perl/Majordomo problem

I'm having a problem with a Perl mail filter and Majordomo. The filter works just fine until I send a message to a Majordomo list. Then it bounces with the following error: Insecure dependency in piped open while running setuid at /usr/local/bin/batemail line 201. 554 5.3.0 unknown mailer error 29 Line 201 in the filter is: if (!open(STDOUT, "|$MAILER $argstr")) I'm on SuSE 7.3. I'd appreciate any thoughts anyone might have. Thanks! Ken