I have a titanium Power Book running os x 10.4 which up till this morning worked fine. this morning on startup, when it gets to where the blue progress bar moves all the way to the right and says "Starting Mac OS X" it does not go any further, no matter how long you let it sit. I have restarted the machine with the single user prompt several times, ran the "fsck -f" thing several times and it does not seem to fix the problem at all. the only weird thing it says in single user mode is "Firewire (OHCI) Apple ID 18 built-in: no valid selfIDs for more than 2 minute after bus reset". Any help would be awesome. thanks for reading!