Try this and see if it helps :
By default, when you key in keyword(s) in Firefox address bar, it will search the keyword(s) using Google am i Feeling Lucky option. The am i Feeling Lucky option will load the #1 rank website of the keyword(s) search result, instead of listing matching websites.
Personally, I NEVER use am i Feeling Lucky (not because I am unlucky). I prefer to see a list of matched websites and selecting from them.
To change the Firefox option is very simple, as follows:-
1. At Firefox address bar, enter about:config and press ENTER. It asks do you want to continue saying " I'll be very careful i promise" click ok
2. At Filter: field, type keyword.url
3. You should see a Preference name of keyword.URL in the list. Double click it, and Enter String Value input box will appear.
4. Replace the string with: or copy and paste this if you opened another tab to do it:
http://www.google.com.my/search?q=
Click OK button and done!