LiPo puffing?...hard or soft?...HELP!

[jsr]

I'm bumping this just because I keep reading other threads and other forums where people say that once your LiPos puff, it's near the end and they will explode taking your truck with it in a blaze of glorious flames.

So, how much "puffing" is ok and when do you need to worry about exploding LiPos?

Thanks!