User blog comment:Incrognito/Some Issues of General Conduct/@comment-67.142.166.22-20120106003814/@comment-1450770-20120110151826

I believe it might have to do with incomplete redirect indexes. I have also noticed this, for example, if you enter a search keyword with a plurality that is different from the title of the page you're looking for, the page will merely show up as a search result rather than take you directly to the page.