You can’t use http://codex.wordpress.org/Giving_WordPress_Its_Own_Directory to move from a subdomain to a domain. WordPress can be moved up or down a directory level, but the same technique can’t be used for subdomain – really a different domain – to another domain.
Follow Moving WordPress « WordPress Codex and WordPress Serialized PHP Search Replace Tool.
The main issue is you have to change URLs in the database – both in site options and everywhere else, such as theme options, widget data, etc. – and change them correctly by deserializing and reserializing php data. Don’t change URLs in a text database dump; that will break things such as serialized data. And you can’t simply change the two URLs in site settings; you need to change them throughout the database.
And, don’t forget to change hardcoded URLs in style sheets and theme php files.