FSCK gave this result
**Checking catalog file.
disk0s2: I/0 error.
invalid key length
**volume check failed.
/dev/rdisk0s2 (hfs) exited with signal 8
My mac book air starts to boot up (the wheal starts to turn for about 30s) than it just turns of
it was working fine a few hours ago, i did a hardware test (every thing was OK) and after that the problem occurred
PRAM and SMC reset did't help
1.6 GHz, 2 GB, 80 GB, Mac OS Leopard