Bukkit

What steps will reproduce the problem?
1. Create arena as normal.
2. Have players join arena
3. Start Areana

What is the expected output? What do you see instead?
The plugin to work properly and not have players to fall through the floor.
Players fall right through and the last player to hit the bedrock keeps falling. They are also the winner

What version of the product are you using?
0.9.2.1

Do you have an error log of what happened?
No errors at all

Please provide any additional information below.