Hi! I had a Macbook Air A1237 with Leopard Mac OS installed on it. After about 3 years the login times started to increase considerably and gradually. Until a few months ago the MAC refused to start at all. I let him like tens of minutes to do boot sequence but it refused to start. Usually the Mac froze after the Apple image with a rotating circle disappeared and then 2 screens, 1 blue and other with lighter blue image appeared. The HDD seemed to struggle to do something as those 2 blue screens alternatively appeared one after other without end. I read some online hints, I started the Mac in safe mode, it did something... then those blue screen stopped to appear at all, the Mac just shut down. I installed a new operating system, the Snow leopard and everything seemed to be fine until I run the Disk utility program that says the SMART status for the drive is failing and the hardware has a problem that can't be repaired. I also used other HDD utility programs and the majority of them said the Hdd has a lot of bad sectors and the SMART is also failing for the Raw read error rate only. But the Mac works fine. The HDD also works like it has no problems. Now I wonder if that SMART error is really true or is a misinterpretation of the fact that the Leopard OS did not started properly dozens of times in that period prior to install the Snow Leopard??