Question

SettingsView *settings = [[SettingsView alloc] initWithNibName:@"SettingsView" bundle:[NSBundle mainBundle]];
settings.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
[self.navigationController presentModalViewController:settings animated:YES];
settings = nil;
[settings release];

Instruments claims that the following line is leaking

[self.navigationController presentModalViewController:settings animated:YES];

Answer 1

You need to release settings before setting it to nil, not after!

What you’re doing now is the same as:

settings = nil;
[nil release];

So the -release is being sent to nil, not to your SettingsView object. (And sending any message to nil is a NOOP).