The sneakoscope worked because it weant off when George and Fred were putting beatles in Bill's soup, when Ron used the owl. I think it weant off because of dementors or Scabbers or the Lupin being a werewolf, but I think the sneakoscope picks up on emotions of secrecy and Lupin would be secretive if he di not need to be, but if Peter saw Remus he would be frightened and wish to hide. So when first seeing this thread I thought it was because of dementors, but after reading the one about Scabbers I thi nk that one is the best.