If nobody has told you this yet, it is time for you to buy a new helmet. The one you have is essentially useless.
You make a good point and I have been wondering about this myself. I have a Gyro G10 and I got a pretty good concussion wearing it, however when I look at the foam, it is all intact and not cracked..at least not that I can see. Does that mean it is still okay, is isn;t it junk now?