I attempted to login the other day, typed in my name and password, ibook began the login process and then froze. Shut off computer began process again, same result. Logged in using wife's login and everything worked just fine. Tried mine again, nothing! Finally used my original Panther disk and was able to change my password, but now I have a totally new login with all original settings, no email, no Safari bookmarks, nothing

Checked in my Finder and found a File Vault icon, which had all my files, including mail, music, pictures etc.
Took time and rebuilt everthing, didn't take too long, thanks to File Vault information.
I am wondering what happened, can't figure it out. Anyone have any ideas?
I have an 800 ibook, with 640 memory and run Panther OSX most recent version.
Thanks