Hi!
Have the same issue after upgrading to 6.6.2.0 - and it's still there with 6.6.3.0.
I made a case with support, and as expected they weren't very helpful. They requested a packet trace of the radius traffic. I haven't had the time to do that yet, but I doubt there is any traffic there. We don't use Radius accounting, and we have no problems with our radius authentication at all. Everything works as expected, except the log messages.
I also got a question about expired certificates, but as far as I can see, I have no certificates that expire untill 2017 at least.
I seem to remember that the 169.254.x adresses are adresses assigned to the AP's on the inside of the encrypted tunnel. We also have a team, and about 300 AP's.
Since it doesn't seem to affect anything here, I haven't bothered to pursue this, but it's still a bit annoying to have my logs flooded. And we are at least a few users experiencing the same, so hopefully HP will figure it out before we are forced to move to Aruba ;)