I remembered this from playing with my brothers on the 800xl. MULE rocks!
Downloaded as described and tried to have a game but it crashes after selecting training game/length and I get the message;
MuleException
org.newdawn.slick.SlickException: Failed to load image from: images/followers/sprite-mule.png
What have I done or not done to cause this?

I am a noob with linux so this may well be the problem; I'm running Ubuntu Karmic Koala. I'm not sure how to post the logfile, so I've stuck it in here; hope that isn't the wrong thing to do?
cheers,
david
INFO [Properties.<init>] VERSION: 1.2.4
INFO [Properties.<init>] Classpath: ./data.jar
INFO [Properties.<init>] Java VM: 16.3-b01
INFO [Properties.<init>] Java Runtime: 1.6.0_20-b02
INFO [Properties.<init>] OS: Linux 2.6.31-22-generic i386
INFO [Properties.<init>] Java Library Path: lib
INFO [Properties.<init>] Max Memory: 259522560
INFO [Properties.<init>] Avaialble Processors: 1
INFO [PropertiesBase.readFromFile] Reading Settings from file settings.txt
INFO [Settings.<init>] Settings file not found: settings.txt (No such file or directory)
INFO [SubstanceLoader.initLookAndFeel] Window Skin: Default
INFO [SlickLogSystem.info] Enabling Adam's AI (Not Mac)
INFO [Main.main] lpSolve: 5.5 Release 0 Build 15
INFO [SoundPlayer.initialize] Initializing Sound System
INFO [SlickLogSystem.info] Initialising sounds..
INFO [SlickLogSystem.info] - Sound works
INFO [SlickLogSystem.info] - 64 OpenAL source available
INFO [SlickLogSystem.info] - Sounds source generated
INFO [MasterClient.close] MasterServer: Closing...
INFO [MasterClient.close] MasterServer: Closed (37ms)
INFO [MetaFrame.<init>] Creating Meta Frame
INFO [MapSkinParser.findSkins] No extra skins found
INFO [MasterClient.logSend] MasterClient: Sending Enter Lobby
INFO [Login.dispose] Disposing login
INFO [Main.main] Creating game container
INFO [MuleGameContainer.<init>] LWJGL Version: 2.4.2
INFO [MuleGameContainer.<init>] Desktop Display Mode: 1024 x 768 x 16 @60Hz
INFO [MuleGameContainer.<init>] Current Display Mode: 1024 x 768 x 16 @60Hz
INFO [MuleGameContainer.<init>] Display Adapter: null
INFO [MuleGameContainer.<init>] Display Driver: null
INFO [MuleGameContainer.setVSync] Setting vsync: true
INFO [MuleGameContainer.<init>] Setting pixel format
INFO [MuleGameContainer$1.run] Pixel format: Samples=0 Alpha=0 Depth=8 Stencil=0
INFO [MuleGameContainer.<init>] GL Vendor: S3 Graphics Inc.
INFO [MuleGameContainer.<init>] GL Renderer: Mesa DRI SuperSavage 20061110 x86/MMX/SSE
INFO [MuleGameContainer.<init>] GL Version: 1.2 Mesa 7.6
INFO [MuleGameContainer.<init>] GL Max Texture Size: null
INFO [SlickLogSystem.info] Use Java PNG Loader = true
INFO [MuleGameContainer.<init>] Display finished
INFO [Main.main] Entering game loop
++++++++ END OF INITIALIZATION +++++++++++++++++++++++++++++++++++++++++++
INFO [MetaFrame.startGame] Starting game number 0
INFO [MetaFrame.startGame] Entering Game - ID: 0, Name: TRAINING-39996, Address: 127.0.0.1, Is Host: true
INFO [MuleGameContainer.init] *** Starting Game ***
INFO [MuleGameContainer.init] Display: Created=true Active=false Visible=true
INFO [MuleGameContainer.init] Making display the current GL context
INFO [View.<init>] Creating view...
SEVERE [SlickLogSystem.error] java.io.IOException: Attempt to allocate a texture to big for the current hardware
at org.newdawn.slick.opengl.InternalTextureLoader.getTexture(InternalTextureLoader.java:293)
at org.newdawn.slick.opengl.InternalTextureLoader.getTexture(InternalTextureLoader.java:231)
at org.newdawn.slick.opengl.InternalTextureLoader.getTexture(InternalTextureLoader.java:171)
at org.newdawn.slick.Image.<init>(Image.java:196)
at org.newdawn.slick.SpriteSheet.<init>(SpriteSheet.java:129)
at org.newdawn.slick.SpriteSheet.<init>(SpriteSheet.java:115)
at com.turborilla.mule.view.SpriteLoader.initialize(Unknown Source)
at com.turborilla.mule.view.View.<init>(Unknown Source)
at com.turborilla.mule.view.MuleGame.init(Unknown Source)
at com.turborilla.mule.view.MuleGameContainer.init(Unknown Source)
at com.turborilla.mule.Main.main(Unknown Source)
SEVERE [Main.logError] com.turborilla.mule.MuleException: org.newdawn.slick.SlickException: Failed to load image from: images/followers/sprite-mule.png
at com.turborilla.mule.view.MuleGame.init(Unknown Source)
at com.turborilla.mule.view.MuleGameContainer.init(Unknown Source)
at com.turborilla.mule.Main.main(Unknown Source)
INFO [MasterClient.logSend] MasterClient: Sending Game Log
INFO [MuleGameContainer.release] Closing game.
INFO [MuleGameContainer.release] *** Game Over ***