I solved the problem by downgrading the firmware on the IAPs to 6.4.2.0-4.1.1.1_46936 after I noticed many people having problems, and that the release I was using was pulled from the support site.
Nice to see they pulled it to prevent issues with CPU usage on the IAPs, but I wonder if I missed the announcement or why support didn't snap to my problem in the first place?
What's the best way to stay abrest of things like this? We had problems with our IAPs and the new firmware for over amonth, and I had to dig around quite a bit to discover a working solution.