Super Mario RPG - Question about a chest

[m4tt]

I'm playin through SMRPG for the heck of it, and I'm in need of some help. I'm at the Land's End and there is a chest I want to get:

http://kingd0rk.com/files/image144.gif
It's above Mario's head, out of the screen. There's also a hidden chest in the upper left hand corner that I'd like to get. Now I have the Nintendo Players guide for the game and it states that you need to reveal a floating block which will take you up to the chest.

http://kingd0rk.com/files/image145.gif
This is where the block will be. So Mario jumps to make it appear!

http://kingd0rk.com/files/image146.gif
And there it is! Once the block has appeared the guide says to jump into the cannon to the left, and have it fire you onto the block. Once on the block, it should magically float to the chest!

http://kingd0rk.com/files/image147.gif
Here is Mario on the block. I have my rom just sitting there. Mario bobbing up and down on the block. The block hasn't moved in 5 minutes. Am I doing something wrong? Will I never be able to get this fabulous chest?

I've beaten this game 10+ times and I've NEVER gotten that chest, I want to get everything I can this time through, and I will not leave the Lands End until I GET THIS CHEST!

Any help would be appreciated. :3

[Agent Proto]

Oh, for crying out loud!

http://img.photobucket.com/albums/v356/proto3k2/mrpg-help.png

[Kawaii Ryûkishi]

Yes.

[m4tt]

Well that seemed easy enough. Nintendo guide never even mentioned that platform.. Well thanks!

[Erdrick Holmes]

What's in the treaasure box?

You made me wanna play that game after I finish Xenogears.

[m4tt]

It was a frog coin! WOO!

[nihowma buffet]

mmmm frog coin.

btw, i hate the hidden chest in mushroom castle, where you have to jump on toad's head to get up above the doorway. arg.