link not getting recoginzed in in firefox, when i type something www.yahoo.com it does not take this as link, it works fine in IE

i believe it used to work in firefox too

i am using
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.0.1) Gecko/2008070208 Firefox/3.0.1

please helpe and i knew that it will work in your example i just wanted to know what may be the issue.