Just to share info:
NetBackup error code 24 when during backup of RHEL 5 client (with ASL).
try: telnet <client_ip> 13782 from Netbackup server
a) no connection
fix client: disable SELinux or open firewall ports for netbackup
b) bpcd: error while loading shared libraries: libnbmangle.so: cannot enable executable stack as shared object requires: Permission denied
fix client: execstack -c /usr/openv/lib/libnbmangle.so
About ASL? LOVE IT!