Is it normal for video to come to a complete stop (not pause but studded then pause) when active airbag protection is enabled and when I slightly tap/move the thinkpad?
Or do you think there is something wrong with the hard drive? I lowered the sensitivity to medium, because when I was watching the video on my lap, every move, even scratching my head would cause it to stop. I know the drive stops spinning, but should it affect video playback this much? Doesn't the video mostly play from the RAM or buffered more than few seconds? It is better with lower sensitivity.

it is normal, and you can check when the active protection system parks the hard drive heads (doesn't stop spinning though) if you have the icon in your tray. play the video, and move your laptop. the play icon should change to a pause icon. videos are only buffered for a very short time and are played from the hard drive, generally.

you can also disable the active protection system while you're watching videos, then enable it after.

Thanks. I really thought it should be buffering longer for some reason.

Mine also has a setting, a box to check, that tells the system to "adaptively ignore frequent repetitive shocks as those experienced when in a train or automobile." Check to see if yours has that, too.

It automatically recognizes pattern movement like walking, cars, etc. but generally car movement is not really repetitive at same pace.
Anyway, whenever I start watching something I just disable it or lower the sensitivity. If I forget to disable it, first pause reminds me. I just need something to remind me to turn it back on. Is there anyway to add different values to temporary suspension setting? The max is 3 minutes.