Iphone NsMutableArray Count

Question

I have a struct SystemStruct *sharedStruct = [SystemStruct sharedSystemStruct]; implemented as a singleton, to share 3 Arrays.

the problem is that when i try to count the array's objects the system crash. es:

This code Crash:

- (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section 
{
 SystemStruct *SharedStruct = [SystemStruct sharedSystemStruct];
 return SharedStruct.path.count;
}

This Code Work:

SystemStruct *SharedStruct = [SystemStruct sharedSystemStruct];
NSLog(@"%d", SharedStruct.path.count);

How can i return the correct array count?