chrono cross - earth dragon

hi forum :D

i have a little question about chrono cross...

well, im trying to get to the earth dragon just one rockroach is blocking my way... i could put 2 rockroaches in the sandjets but the last one i cant move.

the first one i used explosive and it fell into one of the holes. the second one i fought and then threw it into another hole.
but the last... down in the sand ... after i defeated it, it tells me "push it towards the sandjet to stop the flow" or sth like that... but IT DOESNT MOVE! :mad2: :cry: ive tried everything and i dont know what to do more. thnx for helping me (if u can :cool: )