[Tracker] Alternate word search with "OR"

[Jin Suh <jinssuh yahoo com>]

Hello,

I have a question for you gurus about the tracker.

I have 3 search terms such as "text", "document", and "setting". I want to search one or more of
these words. 

When I entered a word "text" (without quote) in the search entry, I got 244 results.
With "document", 64
With "setting", 49
When I did "text OR document", 52
When I did "text OR document OR setting", I got 26 but I expected more results.
Both "text document setting" and "text, document, setting" are 26 same results as above with "OR".


Could someone explain to me why? How could I do to search with "OR" (one or more words, alternate
words) like google?

I appreciate your help.
Jin