eah dude, that same thing happened to me, except in the screen section, not the kief compartment. It hasn't happened any other time, but the other day I bought an eighth o' dank from this guy and when I looked at it looked small as shit, but when i went home to tear it apart to put in my grinder, it was the stickiest, densest nug i have ever seen, seriously. Anyways, I think what happened was when I was trying to twist the top to grind it, it wouldnt fucking budge and i think I tried to twist it so hard that i just screwed it on super tight and couldnt get it. heres what i did, put the whole grinder in the freezer for 20 minutes, then let it thaw back out a little and just work at it, it should come undone.