MacBook Pro Core 2 Duo reboots after I close lid


MacBook Pro Core 2 Duo reboots after I close lid
I have a MacBook Pro 15" Core 2 Duo 2.33 GHz running Mac OS X Tiger 10.4.9. It's about 6 months old. For the last couple of months, I've noticed that every once in a while, when I close the lid, moments later I hear the reboot chime. If I reopen the lid, I see the machine booting up. Any unsaved work is lost. It happens maybe once every week or two and I do not know how to reproduce the behavior.
A little googling shows that I'm not alone; others have experienced this problem. See starting/
I haven't seen any threads discussing this problem here on Apple's discussion board. Is the problem acknowledged by Apple? Is any fix known? Should I take my laptop in for service? Will Apple help me if the problem is not reproducible?
Thanks for any advice you can offer.
MacBook Pro   Mac OS X (10.4.8)  
I've had this happen about 3 times in the 3 weeks i've had the computer. This morning when it happened, i lost about an hour's worth of typing in MacJournal. You don't need to save in MacJournal, it saves everything if you set it too, like Sticky notes. Unless the computer crashes apparently. Due to this happening, i ended up finding a great keystroke recording backup program called BackTrack, but i digress.
Now that you mention it, i will have to pay attention to whether it's always plugged in to the power adapter when it does this, because something i've noticed several times, though intermittently, is that sometimes when the power adapter gets pulled on, or comes loose, the display dims a little. That's never happened on any of my other previous 3 laptops. I CAN reproduce that, i did reproduce it when it happened tonight, though it doesn't always happen. But the dimming may be a sign that the computer wants to go to sleep or temporarily shut off. I know there are some serious problems reported with the (otherwise very cool) magsafe adapters--I read so many reports of adapters that suddenly after several months of normal use, would spark, disintegrate at the junction wiht the computer, become hot and melt, and other things of that nature. If you look up the magsafe adapter in the apple store and read the user reviews, more than half report such problems.
So maybe this is related to the random spontaneous reboots. I've never had a computer do this before either. Has anyone noticed if there's any pattern in terms of it being plugged in or not?
Here's another thread about the issue:
MBP 2.16 15" 1Ghz,PBG4 1.5Ghz 12"512MB 80GB, PBG4 1Ghz12" 768M 80G   Mac OS X (10.4.9)   AirportXreme,AirportXpress,iPod,iBook12"dualUSB
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