Comment 5 for bug 504337

Really, strictly speaking this is not a bug. The quick search bar if you click on the magnifying glass says 'Subject or Addresses contains', and if you go to 'Advanced Search' you'll see this rule is defined as 'Any of the Subject, Sender and Recipient' contain the *whole* specified string. This is never going to be the case if you use keywords from both the Sender and the Subject. Unless I've misunderstood your definition of the problem. It would be good to get some screenshots showing where you entered the terms and which results you did and didn't get.