RB500 and 3.14 = 100% CPU

I have two units side by side on one of my mountain sites. One unit is a RB500 (model RB532a) running firmware 2.17 the other is a RB500R5 (model RB532a as well) running firmware 2.17 as well. When i upgrade the standard RB500 to 3.14 the CPU utilizatoin hits 100% the moment the wireless interface is enabled. The RB500R5 works perfectly. When i downgrade back to 3.13 everything works fine, then i upgrade again to 3.14 and boom 100% CPU as long as the wireless is enabled. Is there any known issues with the standard (older RB500) and 3.14?

Thank you in advance..

Have you upgraded the rb532 bios? That might fix it.