changing the same singleton array form all classes ?

Question

Hi

just made my firs singleton and i am trying to figure out something.

i have a categories array that is stored in the singleton.

when i need it i use :

 Mannager *sharedManager = [Mannager sharedManager];
 categories = [[NSMutableArray alloc] initWithArray:sharedManager.categories];
[sharedManager release];

now i understand that when i am adding an object to "categories" array, i am not influencing the "sharedManager.categories" that is stored in the singleton. so changes that i make in 1 view wont be available in the others.

1. am i right?
2. if so what can i do to change the original array?

thanks shani