UITextField and NSString don't like spaces?

I'm having a bit of a problem whereby anything entered in a UITextField that's passed into a method in a new view controller (which the app subsequently moves to) seems to crash the app if the entered text contains a space and I try and write that string to NSLog or to the new view controller somewhere.

For example, I've got a view controller with: (pseudo-code)

Code:

UITextField *myTextField;

[newViewController handleText:myTextField.text];

And a new view controller with:

Code:

UILabel myLabel;
    
- (void)handleText:(NSString *)myText {
     NSLog([NSString stringWithFormat:@"passed text: %@", myText]);
     myLabel.text = myText;
}

If the text I enter into the UITextField doesn't contain a space, everything works perfectly; but if I do enter a space weird things happen - the NSLog entry causes the app to crash, and setting the text of the label displays something weird, like "( )". I've tried using either %s or %S in place of %@, but then I just get really strange results of bizarre character strings.