Did the kABI change on RHEL6.1 or RHEL6.3, leading to 3rd party kernel modules not beeing loaded on the new kernel?

Issue

• Did the kABI change on RHEL6.3, leading to 3rd party kernel modules (i.e. from Symantec) not beeing loaded on the new kernel?
• On http://www.symantec.com/business/support/index?page=content&id=TECH75506 we see

"Red Hat Enterprise Linux 6.3 is currently not compatible with Storage Foundation High 
Availability Solutions 5.1SP1,5.1SP1PR2, 5.1SP1RP1 & 5.1SP1RP2 releases due to symbol 
changes used within the new kernel."

This sounds strange as I was convinced that binary compatibility between RHEL minor releases was always guaranteed. Can you please provide information about this topic?
* When trying to install VxVM (Symantec Storage Foundation) using insmod, an error is printed on the screen:

[root@rhel6.1 ~]# insmod /etc/vx/kernel/vxdmp.ko.2.6.32-71.el6.x86_64
insmod: error inserting '/etc/vx/kernel/vxdmp.ko.2.6.32-71.el6.x86_64': -1 Unknown symbol in module