Firefox: Using Multiple Keywords in Address Bar to Open Web Page

Hi,

I'm using Firefox 3.5.5. In older versions, I was taken directly to web pages after going to the address bar and typing in multiple keywords (separated by spaces), and then hitting the 'go' arrow.....When I try that now, I get "url is not valid and cannot be loaded".

In the past, for example, I could type MLB Scores ESPN, and upon hitting the 'go' arrow, I'd be taken directly to ESPN's MLB Scoreboard.

Perhaps something can be tweaked within Firefox's About:Config ?

Thanks for any help.