Gunnar - those requirements for Auth Manager and OV NNM are probably tied to the kernel package, rather than the Red Hat release number, so pinning the redhat-release package won't address the fundamental problem.
If you use the yum-versionlock RPM you can lock the kernel package at a specific version to support the vermagic in the drivers from HP or RSA, or modify the /etc/sysconfig/kernel file to set "UPDATEDEFAULT=no" to prevent new kernel package installations from changing your default boot kernel.
This way you'll get all the necessary security and stability patches, but without breaking poorly-designed apps that can't cope with kernel changes properly.