Macbook unibody reboots by itself

I have a 3 months old macbook unibody 2.0GHz, and the last week it has randomly started to reboot by itself. I can't describe exact the problem as it always happen when I'm not with it, but I get back and it has rebooted. I checked the consol but it is not showing any messages during the time. I noticed that there are many other errors about various things throughout the day. Is this common?

In any case, does anyone of you guys have any idea what the problem could be and how I resolve it? Thank you!

That type of problem can be difficult to track down unless you can pin point what is causing it. Rebooting of the machine can be caused by a power supply defect, overheating, AC main power fluctuations, bad memory, and so on.

You might want to boot your machine with the install media and do a hardware test. Follow the directions given in this Apple KB article: Link

Regards.

Hi again. I ran both the short and extended hardware diagnostics and all it said was that no problem could be found. I'm seriously starting to worry now because it is still restarting. Here is an extract from my console. All I know is that the computer restarted somewhere around this time. Can anyone help?

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3/21/09 11:12:53 AM com.apple.launchd[1] (com.apple.UserEventAgent-LoginWindow[376]) Exited: Terminated
3/21/09 11:12:53 AM com.apple.launchd[1] (0x10c480.BezelUIServer[394]) Exited: Terminated
3/21/09 11:12:53 AM com.apple.launchd[398] (com.apple.AirPortBaseStationAgent) Unknown key for boolean: EnableTransactions
3/21/09 11:12:54 AM com.apple.FolderActions.enabled[401] launchctl: Error unloading: com.apple.FolderActions.folders
3/21/09 11:12:55 AM Dock[411] _DESCRegisterDockExtraClient failed 268435459
3/21/09 12:14:02 PM com.apple.launchd[398] (com.apple.pboard[410]) Exited: Terminated
3/21/09 12:14:02 PM com.apple.launchd[398] (com.apple.UserEventAgent-Aqua[408]) Exited: Terminated
3/21/09 1:23:24 PM com.apple.launchd[1] (0x10b9f0.BezelUIServer[494]) Exited: Terminated
3/21/09 1:23:24 PM com.apple.launchd[1] (com.apple.UserEventAgent-LoginWindow[486]) Exited: Terminated
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Take it in. Kernel panics are software issues, but you would see a black logo with text on the screen.

Spontaneous reboots are usually caused by something overheating or 2 wires touching that aren't supposed to. (A mix of those two problems was behind the infamous "sudden shutdown syndrome" on the original white macbook).