Hi there,
I can indeed see your blog at http://goyippie.wordpress.com/. The domain mapping/unmapping takes some time to propagate (up to 72 hours, but usually much less time), so you were probably just within that window when you checked.
If you are still having problems seeing your blog, you will want to clear your cache. Here is more information about how to do that:
http://en.support.wordpress.com/browser-issues/
If that doesn't help, just let me know, and we'll proceed from there!