pt 10 or 11 not working after OS 10.6 -> 10.8.5 upgrade

can this be true??



after an system upgrade from OS 10.6.7 to 10.8.5 protools no longer works



i did a fresh install of PT 11.3.1



i cannot record more than 6 min untli i get a CPU overload AAE -6101



16tracks no plugs

1024 buffer

delay comp off



powerbook

2.53 GHz intel core i5

4GB 1067mHz DDR3





same setup works with reaper, logic, …



any ideas?

i'm desperate...