Need Help

I was checking my gmail yesterday and all of a sudden the firefox window just closed by itself. I tried re opening firefox but the icon just keeps bouncing and then nothing happens. I tried re starting my powerbook and I ran into some other problems. Firefox still wont start, if i use safari i can only browse for about a minute or two then a grey screen comes on an tells me to restart the powerbook. Every time i restart the powerbook I get the same scenario. At some point my mouse freezes or i get the spinning rainbow ball.

Any advise will be appreciated. Thank you.

I would bring it up to an apple store if it is convenient. They normally know what to do at the Genius Bar!

Try updating... I know my safari would close at random times till I updated.