I basically have the same problem. A friends HD was acting badly. Ran Disk Repair Util many times. Says disk needs repair but it won't repair it.
I re formatted and installed 10.8 but that hasn't fixed it.
Ive tried partitioning it and that won't work.
Now I'm trying to get system 10.8 to reinstall and it says the disk is locked. Your fix requires Terminal, is that right? How do I open terminal to run your fix?
Please help if you can. Disk Warrior couldn't fix it. I think the disk is bad. What do you think?