Cannot get adobe CS applications to launch


Has anyone got any ideas why i cannot seem to get illustrator CS to launch...the software loads ok but when i try to start the application the icon shows in the dock for 5-10 secs then clears. I have checked the crash log in the console and the error message is: KERN_PROTECTION_FAILURE. I tried going back to basics in case of conflicts with other software by backing up all my files then reinitialised the hard drive and reinstalled OS 9.2 then OS 10.3.2 upgrade and then reloaded illustator - but still the same result! I have tried resetting permissions and deleting illustrator preferences but still no luck. Could this be faulty memory thats causing the problem? im using an imac g4 with 768mb ram...