Kernel API
Security products such as these will use bits of kernel API which userspace programs don't. But this gets to the core of "what constitutes an OS version change?"
At one extreme, you have Solaris, where the kernel API is guaranteed not to change during the life of a major version. There may be additional API added, but the stuff which is already there cannot be changed. So the stuff which interfaced with the S10 kernel at GA (July 2007) is guaranteed to continue to work OK.
At the other extreme, you have the Linux kernel API, where every minor version change may result in a change of API for modules which interface with it. This isn't a problem for the drivers which are bundled, but external stuff which interfaces with the kernel can break at any point. The job of distributors such as RedHat or Novell is to minimise the pain, so only where their update revision flips over do things stop working.
So the reason these 3rd party bits have stopped working is because they need the Sun model, and actually get the Linux model.


