I see, I guess in next version I should add a red-colored note above the username field that it is advised to contain only alphanumeric characters. But its okay, I understand. I will see what I can do for you.
Well at this point the best idea is to only use alphanumeric characters(A-Z, a-z, 0-9) plus empty space or underscore(" " and "_") characters as your username. The other symbol characters have special meanings in PHP and URL, some can be manipulated by hackers to attack your site and database. So I usually filter them from user input(form or URL), the filtered result may lead to loss or modification of the very symbol you use. In fact, Id say Realitys Madness is a good username to me, I usually am too lazy to type the single quote symbol myself.
But if you really need to use single quote in username, I can find a workaround for you. Send me your FTP login information and I will modify the script on your site and make it work for you, possibly tonight or tomorrow it will be done.