I'm running Lion on a 2008 Macbook Pro that has been having random shutdown issues. This had happened before after the sides of the case cracked. I had the motherboard replaced and the problem resolved for a while, but started up again, recently. Now, it gets hung up on startup and nothing seems to be working. I have a thumb drive with Lion on it, from the app store, but it wont seem to boot from that either. I'm now trying the fsck command in single user mode and after running about 20 times in a row, I still get the final line of "FILE SYSTEM WAS MODIFIED".
Just before that I get, Rebuilding catalog B-tree and then, The volume (my HD) could not be repaired.
Should I keep running sbin/fsck -fy or am I screwed?

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