The beta was announced here. http://www.boonex.com/n/dolphin-7-1-3-beta and specifically stated this. IMPORTANT: this version is not suitable for production sites and there will be no upgrade packs for it. So you cannot upgrade the Beta. You need to do a new install. It was not suppose to be used for a production site.
Well, isn't that just dandy. There's no way to update the files from beta? How different is the final version compared to beta? So, if we keep the beta, we cannot upgrade to another version in the future?