Is it safe to use constant x / y coordinates in iPhone code

I used constant coordinates in the code in several places of my iPhone application, especially when I programmatically create a view by setting the properties of the uiview subclasses.

Example:

UIImage* img = [UIImage imageNamed:@"background.png"];
UIImageView *imgView = [[[UIImageView alloc] initWithImage: img] autorelease];
imgView.center = CGPointMake(160, 175); // --> Are these constant usages safe?
[self.view addSubview: imgView];

I tested it on a simulator, 3G device and 4S, and it works. Should I worry about future device solutions or any other bugs? If so, how do I make this piece of code more secure? Any coding principles here?

Thanks Mbh