Hi j.hanc,

Can you give us more details as to what you mean by "taking over"?

Did it steal your home page? If so, you should take a look at the Knowledge Base article How to set the home page. Your homepage might have been changed by a particular site. Sites like MSN, Yahoo, etc have been know to ask to become your homepage.

There are steps in that article to reset your homepage preferences to default. I would try that first to clear out any strangeness. If that works, you can try setting your homepage again to your personal preference.

Did it take over search as well? You should take a look at the Knowledge Base article Search bar - add, change and manage search engines on Firefox.

If the address bar search has been changed as well, you might want to take a look at Location bar search.

If that doesn't work you should look at the article How to fix preferences that won't save.

Finally, your issue may be because you've been hit with some Malware.

Hopefully this helps!

By the way, if you're really still running Firefox 6.0.2 -- you can confirm the true version in Help > Troubleshooting Information or Help > About Firefox -- you should seriously consider updating to a secure versions of Firefox. Running insecure versions may expose you to more than being taken over!