No Search Results

You probably have a permissions issue. Since you can access the search results from the administrator, the search engine and -index works. Drupal admin search returns all posts, regardless of their status (published, unpublished, draft) or their access (there are many varieties of content access modules).

First, make sure that the nodes are actually visible on your site as a "regular" user: anonymous or loggin. If so, there is an access issue and the sites are not published. Second, make sure you don't have an accessor module like organic groups or domain work: this could be misconfigured or used in a strange way and disable access to content under certain conditions. Third, make sure you are not using any search related modules. Have you installed a module that "enhances" or "cancels" your search? Such a module will not change the behavior of admin-search, but will change what is visible in the search results.

If none of these apply, please submit additional information.