I have Logic 8.02 with Mac Pro ( last years ) with Mackie CUPro. I have 4Gb RAM. I was doing basic comping of takes ( from David's book ). I had recorded acoustic guitar.As in the exercise. It all freezes including the Mackie.Then the beachball spins.It has happened a few times but this time it is going on and on. Multiple instances of Space Designer set it off too.The gents in the shop say it should not be the RAM or the CPU.It used to happen with Kore 2 running but since it's ( Kore 2 )update it had been fine. Am I right in just switching my computer off or should I wait till the ball disappears ? It's still going after fifteen minutes.Worrying. I am relatively new to all this ( 1 year ) but was recapping with the book cos it's good practice.What is the best cure for this ? Thank you for any guidance or pointers as to what I may be ignorant of..