I am working on building a SharePoint Server 2010 Enterprise environment for Demonstration purposes. I applied my custom branded AdventureWorks master page and created a Search Center sub-site like I always do.

I then uploaded some sample documents and performed a Full Crawl. After the crawl completed I opened the site in my browser and attempted a search for what I knew would return results, only no results were found.

Interestingly enough, I then performed the same query FROM the Search Center site and it found 74 results. Weird, I thought. I then noticed in the query string was: http://AWDemo/searchcenter/pages/Results.aspx?k=sharepoint&cs=This%20Site&u=http%3A%2F%2Fawdemo

The &cs=This%20Site&u=http%3A%2F%2Fawdemo portion of the query string was what concerned me so I went to the Search Settings page and checked my settings.

I had the following settings which I expected would work based on my previous experiences:

Enabled Custom Scopes
/searchcenter/pages

Do not show scopes dropdown, and default to contextual scope

/searchcenter/pages/results.aspx

Just to test I changed the middle dropdown from Do not show scopes dropdown and default to contextual scope to Do not show scopes dropdown and default to target results page.

I attempted another search from my home page search box and voila, it worked just as I would expect.