Macbook pro shuts itself down when idle

Hi all, I am new to the MacBook pro and I have noticed that the computer shuts itself down when idle, its not in sleep but just shuts itself off. When I restart it it comes up with a message that it was shut down due to a problem (it does not reference any particular problem). Any ideas on what is happening , anything I can do?

Thanks in advance

Dave

Hi Dave Welcome ....

1st thing you could try is to repair permissions and see what that brings up ...

Applications>Utilities>Disk Utilitiy and select your HD in the left column and then towards the bottom click the repair disk permissions

Do that then post back if you still have a problem

TM

Also include model of MBP and OS u are using, if a used unit did u do a clean install?

I have the exact same problem. I tried to repair the HD also but the problem still occurs. I will leave my macbook pro idle for some time and when I try to use it again it would send me a message that something was wrong and the computer had to shut down. Then it will tell me to press any button to start it back up again. I'm starting to get really frustrated because I've had this laptop for less than 1/2 year. Please advise. Thanks.

Hey, I have encountered the same problem with my macbook pro.
How did you guys finally fix it ?
Thanks. Reply asap!