Macbook AIr 10.6.8 shuts down randomly

Hi all,

I have been using a macbook air for 18 month.
Since the beginning, i have noticed that this macbook air is shutting down "randomly". If I put randomly with quotation marks, it is because the computer is foolowing a kind of a rule: it is not shutting down while I am using it but only when I am not without closing the system. Then, after the screen saver is on, the system is trying to shut down itself and reboot. It can not shut and reboot if there is an unsaved document, otherwise it does.

In the preferences panel, there is nothing programed for this (or I do not know where).
The system is up to date and do not know if there is something I have to do to correct this stuff.

It is annoying because if I am downloading something from internet or if time machine is saving my system : the random shutdown will happen and stop the processes. And it is also annoying by itself

Does anyone have a clue/tip to correct this behaviour? Something I have to check somewhere?

Any help would be very appreciated.
bigbag

A couple quick things to try:

- Do an "SMC" reset:

Intel-based Macs: Resetting the System Management Controller (SMC)

- Repair Permissions (open Disk Utility [in the Applications folder>>Utilities Folder, click on the "Repair Permissions" button)

You could also tell us how full your hard drive (SSD) is. Amount used & amount free.

HTH,

- Nick