Aah. Reclaimer finally reached 1000 posts. :P
Hm. I don't think it takes a while to show up. If I am right then the page is build dynamically, so the option should appear with the 1000th post immediatly.
So, assumed you're looking for that option at the right place (User CP - Edit Profile), then maybe your browser has cached the page and didn't refresh it, so try to do that manually. If that doesn't help, clearing the browser's cache would definitely make sure that the page is coming fresh from the server, hopefully containing the Custom User Title section.
If not, then another possibility is that some admin generally disabled this option for your account. Only god would know why. XD