Ah, now I see that you are trying this on CentOS 5.6. I thought you were on 6.0. php53-mcrypt is a problem, I remember having problems with it myself, that's why I used PHP 5.1 in the CentOS 5.6 tutorial.
IF you search for php53-mcrypt on
http://rpm.pbone.net/index.php3 , you should find packages from rpms.famillecollet.com and dl.iuscommunity.org/pub/ius/archive/Redhat/5.5/ .