What are next steps when fsck reports "could not be repaired after 3 attempts"?
You can try this but please make sure you backup first: 

Boot to single-user mode, hold down the command (i.e. cloverleaf or Apple) and "s" keys as the system begins to boot.

To Debug, Repair, Force (and fix errors automatically)

/sbin/fsck_hfs -drfy /dev/disk0s2


To scan for bad blocks:

/sbin/fsck_hfs -S /dev/disk0s2


Assuming disk0s2 is the one you are looking to repair. (Usually the default "Macintosh HD" drive.)

This should get you back inside your OS. 

This link may help too:
http://www.westwind.com/reference/os-x/commandline/single-user.html