Thread:Extension talk:SphinxSearch/Some pages arent found - and the "second" search is different than the first one/reply (9)

Do you have "$wgSearchType = 'SphinxMWSearch';" BEFORE require_once "$IP/extensions/SphinxSearch/SphinxSearch.php"; in your LocalSettings? That is the only var. that needs to be enabled before the rest of the code is included, though I am considering changing that in the next version.

As for the quick search, try setting $wgEnableSphinxPrefixSearch = true; after you include the extension in LocalSettings.