Hi, I'm using Firefox 10 from vista premium and every time I start an error come as Exc in ev handl: TypeError: this.oRoot.enable is not a function.. so I had to click OK to start browser... IS IT A BUG IN FF?Please HELP as how to FIX THIS..?.

Do you have McAfee Site Advisor installed? Look at add-ons -> extensions and add-ons -> plugins, deactivate them. I just came across the same problem, this worked. And better: after reactivating (after restarting firefox) the error stayed away!
Hope it helps,
dieba