Global site search


I'm a new member, so I might be missing something (i don't think I am, but there could be a chance :wink:,
I have downloaded & installed the global search plugin & the post indexer plugin too. However I can't get the search working globally. The site I'm building s here there are some sub sites, one of which I wrote a test post on it to test this plugin (I did it after installing the plugin, as I saw it only indexes new posts) this post is here

When I do a search on the main site, it doesn't come up in the results.

Any ideas why?