Last week, Mozilla began offering Firefox 3.5 to users who still runing with older version of the browser. Mozilla attempt to get people to updgrade before support expires for Firefox 3.0.
Although user have been able to upgrade to Firefox 3.5 by downloading the new browser or manually triggering "Check for Update" under the Help menu but Mozilla has triggered an automated update offer when people running Firefox 3.0.
According to Mozilla :
"We might send you another offer again in the future, but it won't be for several weeks or months,"