My brand new MacBook Pro is randomly turning off and on when it's unplugged and closed! My new MacBook is performing flawlessly when I'm hard at work - I am using it for high-end graphics and 3D mathematical modeling. What is killing me is that it is randomly turning off and on when it is unplugged and closed. It doesn't matter if I shutdown before closing or just let it go to sleep when it's closed. It is almost like the lid is hitting the power button (is this a problem with the new redesign??). Sometimes it will just turn itself off from sleep mode and sometimes it turns itself both off and on. The worst is when I am biking home from campus and hear the *bong* sound of my MacBook turning on in my bag.

I can sort of recreate the problem when it is plugged in and closed; it will come out of sleep mode and then go back in (while closed), but not actually restart. I *do* think that it's the button...

Has anyone else experienced this? Any known fixes? A way to lock the power button when the notebook is closed? I want to find out if there is something I can do before heading to an apple store.
Thanks a ton!!

(Specs: MacBook Pro5,1, OS X 10.5.5, 2.8 GHz Intel Coe 2 Duo, 4 GB 1067 MHz DDR)