Interesting Problem With Powerbook.

On Thursday I was using my 867 12" PB (firefox and adium open) and firefox froze up on me. I tried to force quit but that wouldn't work so I just shut it off. I came back a few minutes later and it wouldn't get to the login screen so I got out my CD to try and run the disk utility. After about 10 unsucessful tries I got it to verify and fix the disk (should have written down the problem). Unfortunately, this only got me to the login screen and not past it. I gave up hope and had conceeded to buying a new hard drive after Christmas. This afternoon when I gave it one last shot things worked perfectly!

Now that I've backed myself up I'm worried this might happen again. Ideas/suggestions as to what went wrong, how my computer fixed itself and/or what I might be able to do to remedy or diagnose the problem?

Thanks for any help you can provide.