I'm using OS 10.4.11. I have Leopard but when my c...

I'm using OS 10.4.11. I have Leopard but when my computer's hard drive crashed about 6 months ago, i accidentally reinstalled 10.4.11 instead of leopard. Now i'm worried that if i update to Leopard i will lose everything (i did actually ring up the Apple helpline to ask if that would happen, but the dude wasn't really sure ...).

Um, the problem with the diverting facebook has been pretty quiet over the last few days, but i'll be annoyed if it comes back. What causes it?