If IPV6 has been disabled this error can occur:

modprobe: FATAL: Error inserting bonding (/lib/modules/2.6.18-194.17.1.el5/kernel/drivers/net/bonding/bonding.ko): Unknown symbol in module, or unknown parameter

Resolution:

Within the modprobe configuration file where IPV6 has been turned off /etc/modprobe.d/<your blacklist file.conf>

Change the line:

install ipv6 /bin/true
to
options ipv6 disable=1

Bonding module can now be loaded without problems.

Reference:

https://access.redhat.com/kb/docs/DOC-50188