Illustrator crashing since update -

I am running Illistrator CC and after an auto update the program has become so unstable that I can no longer work with it.

If i select diferent menu items, such as New, Preference, Workspace -- it will crash. It was working perfectly for the first couple of weeks after fist instal. Now it is so unstable I have to go back to 5.1!!!

Any ideas?

I reinstalled it after using the suggested icloud clearner app, disabled all my system extentions, disabled 3rd party illustrator extentions, rebuilt with disk utility, deleted and reset the preference etc.

Two monitors both ATI Radeon HD 5870 1024 MB graphic

OS X 10.8.4 (12E55)

Model Name:          Mac Pro

  Model Identifier:          MacPro5,1

  Processor Name:          6-Core Intel Xeon

  Processor Speed:          2.4 GHz

  Number of Processors:          2

  Total Number of Cores:          12

  L2 Cache (per Core):          256 KB

  L3 Cache (per Processor):          12 MB

  Memory:          24 GB

  Processor Interconnect Speed:          5.86 GT/s

  Boot ROM Version:          MP51.007F.B03

  SMC Version (system):          1.39f11

  SMC Version (processor tray):          1.39f11