firefox browser default keeps changing

FireFox3.0 default homepage keeps changing how to stop that

Windows xp home edition
2 Ghz of ram

 

Do you select the desired homepage in tools|options|main in the Startup section?
By default you get "show my Home Page ". Below you get the URL(s). If you have selected the home page, click on the "user current pages" radio button. If you wish to have a "home group" rather than home page, you open separate tabs, and save the pages. My home group consists of three different tabs, and it starts that way every time that Firefox starts.
By the way, other than the names, this behavior goes back to previous related browsers.

 

I did all the above

 

And, also, from what?