NSDateFormatter Memory Leak - objective-c

Question

I am running instruments and it keeps saying that there is a 100% leak on the NSString *date = [df2 stringFromDate:dt]; line. I look at examples from apple and they are basically doing the same thing. Can anyone tell me what I am doing wrong or if the instruments are wrong.
+(NSString *) shortDateToLongDateString:(NSString *) dtString
{
NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setDateFormat:#"yyyy-MM-dd"];
NSDate *dt = [df dateFromString:dtString];
[df release];
NSDateFormatter *df2 = [[NSDateFormatter alloc] init];
[df2 setDateFormat:#"EEEE MMMM d, yyyy"];
NSString *date = [df2 stringFromDate:dt];
[df2 release];
return date;
}
I am calling the method as follows:
for (NSString * dt in uniqueDates)
{
NSString *longDate = [NSString stringWithString:[NSDateHelper shortDateToLongDateString:dt]];
//Do something with the result...
}

Answer 1

My guess is that the function is being executed in a secondary thread that doesn't have an active NSAutoreleasePool. If you look in the console log you'll probably find "just leaking" warnings printed (though without anything in the way of info on where the leak is).
Implement the method more or less like this:
+(NSString *) shortDateToLongDateString:(NSString *) dtString
{
NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];
NSDateFormatter *df = [[NSDateFormatter alloc] init];
[df setDateFormat:#"yyyy-MM-dd"];
NSDate *dt = [df dateFromString:dtString];
[df release];
NSDateFormatter *df2 = [[NSDateFormatter alloc] init];
[df2 setDateFormat:#"EEEE MMMM d, yyyy"];
NSString *date = [df2 stringFromDate:dt];
[df2 release];
[date retain];
[pool drain];
return [date autorelease];
}