I have a memory leak problem that just can not understand! Watch this initialization method:

- (id)initWithNomeCompositore:(NSString *)nomeCompositore nomeOpera:(NSString *)nomeOpera {

if (self = [super init]) {

    NSString *pathOpere = [[NSBundle mainBundle] pathForResource:kNomeFilePlistOpere ofType:kTipoFilePlist];
    NSDictionary *dicOpera = [NSDictionary dictionaryWithDictionary:
                                [[[NSDictionary dictionaryWithContentsOfFile:pathOpere]
                                objectForKey:nomeCompositore]
                                objectForKey:nomeOpera]];

    self.nomeCompleto = [[NSString alloc] initWithString:nomeOpera];
    self.compositore = [[NSString alloc] initWithString:nomeCompositore];
    self.tipologia = [[NSString alloc] initWithString:[dicOpera objectForKey:kKeyTipologia]];
}

return self;}

Then this little variation (note self.tipologia):

- (id)initWithNomeCompositore:(NSString *)nomeCompositore nomeOpera:(NSString *)nomeOpera {

if (self = [super init]) {

    NSString *pathOpere = [[NSBundle mainBundle] pathForResource:kNomeFilePlistOpere ofType:kTipoFilePlist];
    NSDictionary *dicOpera = [NSDictionary dictionaryWithDictionary:
                                [[[NSDictionary dictionaryWithContentsOfFile:pathOpere]
                                objectForKey:nomeCompositore]
                                objectForKey:nomeOpera]];

    self.nomeCompleto = [[NSString alloc] initWithString:nomeOpera];
    self.compositore = [[NSString alloc] initWithString:nomeCompositore];
    self.tipologia = [[NSString alloc] initWithString:@"Test"];
}

return self;}

In the first variant is generated a memory leak, the second is not! And I just can not understand why! The memory leak is evidenced by Instruments, highlighted the line:

[NSDictionary dictionaryWithContentsOfFile:pathOpere]

This is the dealloc method:

- (void)dealloc {
[tipologia release];
[compositore release];
[nomeCompleto release];
[super dealloc];}