It's a bug. I fixed it http://cloud.blockland.us/MarioLandFun-r129.zip
Alright, thanks!
Okay, as for the ladder setup thing, I've experienced something similar. On a few occasions, I've had the ladder move an extra position after it should have stopped moving. So, let's say that I enter the bonus game and Mario cycles from top to bottom once, returns to the top, and then when he gets back to the bottom again I stop him. The ladder should always be on the floor above him, bridging the x2 bonus floor and the x1 bonus floor, not coming between him and the x3 bonus. However, for reasons I cannot explain, the ladder will sometimes be moved to the floor he's at, the bottom one, without the blocker object being in place which would force him to go up and get the x2 bonus. This allows the player to run him forward to get the x3 bonus and then run back to the ladder, head up to the upper level, and grab the x2 bonus before being forced out of the bonus game.
I hope this helps clear up how to figure out this issue.