The

macro only works with lowercase terms. For example, the search for "test" will find pages with title "test", "Test", "TEST" and so on, but the search for "Test", "teSt" etc. will find no results.

I've tested this in a local Confluence 3.0-rc1, as well as in local Confluence 2.10.2 an http://confluence.demo.atlassian.com with Confluence 3.0-beta2-r2.