BUKKIT SERVER NEED HELP W/ START_SERVER.COMMAND [MAC ONLY]

Hey Guys I Need Help With My Bukkit Server!

So My Problem Is I Always Get This Error With The Start_Server.command!
Last login: Tue Dec 9 17:37:21 on ttys001
Kris's-iMac:~KristianMain
/Users/KristianMain/Desktop/BukkitServer/start.command ; exit;
Invalid or corrupt jarfile craftbukkit.jar
logout

[Process completed]

Please Help Ive Searched EveryWhere! If You Have Any Idea I Would Like To Know

This Is What I Did...

Mac OS X
Install Java
Since OS X 10.7 Java does not come packaged with OS X. You will need to install java from the Apple's website http://support.apple.com/kb/DL1421
Obtaining the Server Files
To run a server you will need the server jars, i.e. the server files. We will need a place to put the files.
Create a New Folder
Open up finder, and create a new folder in your Home folder named CraftBukkit
Download the File
Download the server files. You can download the latest builds from the front page of the wiki.
Note: Download the stable build if you are not chasing the cutting edge in the development build
Move the File
Move the file from the Downloads folder to the CraftBukkit folder you created.
Obtaining startup script
To easily start the server you will need a startup script. The following is a basic server script to start your server.
Open up TextEdit set it to plain text mode under format and paste the following in
#!/bin/bash
cd "$( dirname "$0" )"
java -Xmx1024M -jar craftbukkit.jar -o true
Save the file
Save it in your CraftBukkit folder as start_server.command
Allow the script to run
Open up Terminal.app
Type into Terminal.app
chmod a+x
Warning Warning: Do not hit return
drag the start_server.command into Terminal.app
hit return
Starting the server
From this point on you can start the server by double-clicking start_server.command.
You will need to run the server once for it to generate some configuration files.
Warning Warning: To stop the server, do not close the terminal/command prompt window. Instead, type 'stop' into the console. Closing the terminal window without stopping the server could lead to corruption of the save files.

I ALSO TRIED THE ALTERNATE HERE...

ALTERNATE METHOD [Only for Advanced Users]:

Open Terminal (Found in Application/Utilities) and paste:
cd ~/Desktop/
mkdir BukkitServer
cd BukkitServer/
curl -LO http://cbukk.it/craftbukkit.jar
echo "cd ~/Desktop/BukkitServer/" >> start.command
echo " java -Xmx1024M -jar craftbukkit.jar -o true" >> start.command
chmod +x start.command
The server is installed on your Desktop, in "Bukkit Server". To start it double click "LaunchServer.command".