Actually, the deal with Graveyard Shift was, back before Relativity Records sold out to Loud Records, they were debating whether or not to drop Still Waters. Sin was the only member that could have promoted the album though so they never released it. Tombstone was killed in '96, and one of the members was killed way back in the early 90's. But Gates and Sin are still alive, Gates got kicked out by Tombstone before the second Mo Thugs album though. So that's why he was never around.
It's a damn shame, they made some unbelievable music.