web search and bing

I have windows 7 home edition and moxilla firefox as my internet browser. My home page is MSN.com. For some reason today when I type in a search word
when I try to press web search nothing happens. If I press bing then it searches for me. I do the best of my knowledge not done anything to change
setting etc. I always was able to press web search before even though the word bing in to the right. Thank you for any suggestions.

I believe Bing is the default search engine for MSN. I just went to MSN.com and both ways it works. Have you tried exiting Firefox and trying again? Or perhaps even a reboot will do it as it seems to be doing OK for me.

Thanks, will try a reboot.