when the computer gets bumped it sometimes turns off when running on a battery, according to the repair manual, it needs a foam gasket to keep it in tighter. This thing's from 1997 and I doubt apple still has these: any equivalents?
I use a piece of folded paperboard that fits VERY snugly against the flat side of the battery and the case stiffener where the original gasket would've gone. It requires a bit of effort to get the battery out now, but it never dies when bumped.