Segmentation fault on applications

I tried to play N (Ninja) on my macbook but it just bounced in the dock then did not open. An error message showed simply saying it failed to launch. Since then i noticed 6 other applications have failed to launch. I opened up console and it said i had a segmentation fault on almost all of them. For NeoOffice it said there was an abnormally exit with error code 78. If anyone has any ideas on what could be wrong please let me know. I have been playing N for a while and would not like to lose all of my completed levels. If you have any ideas please let me know.

P.S. i tried re installing some of the apps but they still will not open.
Also reinstalling Leopard will be my last option