IDEA 8.1 doesn't start with latest scala plugin

I've just updated my scala plugin, and now IDEA doesn't start - it stays at the splash screen. Removing the plugin allows it to start.

I'm on OSX 10.5. Could this be a Java 1.6 requirement (which you can't run on 32-bit-only Gen 1 MB Pros) ?

The log error is this:


2009-03-26 12:34:01,246 [   2549]  ERROR - com.intellij.ide.IdeEventQueue - Error during dispatching of java.awt.event.InvocationEvent[INVOCATION_DEFAULT,runnable=com.intellij.idea.MainImpl$3@318309,notifier=null,catchExceptions=false,when=1238033040707] on apple.awt.CToolkit@920208
java.lang.UnsupportedClassVersionError: Bad version number in .class file
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:675)
at java.lang.ClassLoader.defineClass(ClassLoader.java:520)
at com.intellij.util.lang.UrlClassLoader._defineClass(UrlClassLoader.java:119)
at com.intellij.util.lang.UrlClassLoader.defineClass(UrlClassLoader.java:115)
at com.intellij.util.lang.UrlClassLoader._findClass(UrlClassLoader.java:91)
at com.intellij.ide.plugins.cl.PluginClassLoader.loadClassInsideSelf(PluginClassLoader.java:78)
at com.intellij.ide.plugins.cl.PluginClassLoader.loadClass(PluginClassLoader.java:41)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:374)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:242)
at com.intellij.openapi.extensions.impl.ExtensionComponentAdapter.loadClass(ExtensionComponentAdapter.java:140)
at com.intellij.openapi.extensions.impl.ExtensionComponentAdapter.getComponentImplementation(ExtensionComponentAdapter.java:61)
at com.intellij.openapi.extensions.impl.ExtensionComponentAdapter.getComponentInstance(ExtensionComponentAdapter.java:67)
at com.intellij.openapi.extensions.impl.ExtensionComponentAdapter.getExtension(ExtensionComponentAdapter.java:106)
at com.intellij.openapi.extensions.impl.ExtensionPointImpl.processAdapters(ExtensionPointImpl.java:201)
at com.intellij.openapi.extensions.impl.ExtensionPointImpl.getExtensions(ExtensionPointImpl.java:150)
at com.intellij.openapi.extensions.Extensions.getExtensions(Extensions.java:99)
at com.intellij.openapi.extensions.Extensions.getExtensions(Extensions.java:87)
at com.intellij.openapi.fileTypes.impl.FileTypeManagerImpl.<clinit>(FileTypeManagerImpl.java:163)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:242)
at com.intellij.openapi.components.impl.ComponentManagerImpl$ComponentsRegistry.a(ComponentManagerImpl.java:6)
at com.intellij.openapi.components.impl.ComponentManagerImpl$ComponentsRegistry.a(ComponentManagerImpl.java:10)
at com.intellij.openapi.components.impl.ComponentManagerImpl$ComponentsRegistry.access$100(ComponentManagerImpl.java:66)
at com.intellij.openapi.components.impl.ComponentManagerImpl.a(ComponentManagerImpl.java:73)
at com.intellij.openapi.components.impl.ComponentManagerImpl.initComponents(ComponentManagerImpl.java:107)
at com.intellij.openapi.components.impl.stores.ApplicationStoreImpl.load(ApplicationStoreImpl.java:7)
at com.intellij.openapi.application.impl.ApplicationImpl.load(ApplicationImpl.java:135)
at com.intellij.idea.IdeaApplication.run(IdeaApplication.java:41)
at com.intellij.idea.MainImpl$3.run(MainImpl.java:1)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:209)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:461)
at com.intellij.ide.IdeEventQueue.c(IdeEventQueue.java:35)
at com.intellij.ide.IdeEventQueue.b(IdeEventQueue.java:99)
at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:217)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:190)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:176)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
2009-03-26 12:34:01,253 [   2556]  ERROR - llij.ide.plugins.PluginManager - ComponentSetup for component com.intellij.openapi.components.impl.ServiceManagerImpl already registered
java.lang.Error: ComponentSetup for component com.intellij.openapi.components.impl.ServiceManagerImpl already registered
at com.intellij.openapi.components.impl.ComponentManagerImpl$ComponentsRegistry.a(ComponentManagerImpl.java:24)
at com.intellij.openapi.components.impl.ComponentManagerImpl$ComponentsRegistry.a(ComponentManagerImpl.java:10)
at com.intellij.openapi.components.impl.ComponentManagerImpl$ComponentsRegistry.b(ComponentManagerImpl.java:36)
at com.intellij.openapi.components.impl.ComponentManagerImpl$ComponentsRegistry.access$300(ComponentManagerImpl.java:55)
at com.intellij.openapi.components.impl.ComponentManagerImpl.hasComponent(ComponentManagerImpl.java:50)
at com.intellij.idea.IdeaLogger$1.getInfo(IdeaLogger.java:5)
at com.intellij.idea.IdeaLogger.a(IdeaLogger.java:29)
at com.intellij.idea.IdeaLogger.error(IdeaLogger.java:22)
at com.intellij.openapi.diagnostic.Logger.error(Logger.java:56)
at com.intellij.ide.IdeEventQueue.c(IdeEventQueue.java:8)
at com.intellij.ide.IdeEventQueue.b(IdeEventQueue.java:99)
at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:217)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:190)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:176)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)
2009-03-26 12:34:01,254 [   2557]  ERROR - llij.ide.plugins.PluginManager - ComponentSetup for component com.intellij.openapi.components.impl.ServiceManagerImpl already registered
java.lang.Error: ComponentSetup for component com.intellij.openapi.components.impl.ServiceManagerImpl already registered
at com.intellij.openapi.components.impl.ComponentManagerImpl$ComponentsRegistry.a(ComponentManagerImpl.java:24)
at com.intellij.openapi.components.impl.ComponentManagerImpl$ComponentsRegistry.a(ComponentManagerImpl.java:10)
at com.intellij.openapi.components.impl.ComponentManagerImpl$ComponentsRegistry.b(ComponentManagerImpl.java:36)
at com.intellij.openapi.components.impl.ComponentManagerImpl$ComponentsRegistry.access$300(ComponentManagerImpl.java:55)
at com.intellij.openapi.components.impl.ComponentManagerImpl.hasComponent(ComponentManagerImpl.java:50)
at com.intellij.idea.IdeaLogger$1.getInfo(IdeaLogger.java:5)
at com.intellij.idea.IdeaLogger.a(IdeaLogger.java:29)
at com.intellij.idea.IdeaLogger.error(IdeaLogger.java:22)
at com.intellij.openapi.diagnostic.Logger.error(Logger.java:56)
at com.intellij.ide.IdeEventQueue.c(IdeEventQueue.java:8)
at com.intellij.ide.IdeEventQueue.b(IdeEventQueue.java:99)
at com.intellij.ide.IdeEventQueue.dispatchEvent(IdeEventQueue.java:217)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchThread.java:269)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:190)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:184)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:176)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)