Re: searching plugin directory from WP installation "install new plugin:
At least some plugin author names are not searchable. One reproducible example is using the search term "prelovac" (for Vladimir Pelovac). Searching surname "prelovac" as "term" returns some but not all of his plugins, and also returns 2-3 irrelevant responses which don't contain his name (i.e., the search term).
However, searching "prelovac" as "author" yields no results at all.
Does the plugin repository run on Mediawiki? Perhaps there's a markup problem when plugins are entered.