Cannot start WebIDE due to a faulty plugin

Hello,
I'm using an evaluation version of the WebStorm IDE v5. I was trying to install a few javascript related plugins and after restart I was greeted by an error:

Fatal error initializing class com.intellij.openapi.actionSystem.ActionManager:
java.lang.VerifyError: class git4idea.GitVcs overrides final method getName.()Ljava/lang/String;

Another issue would be that I am trying to close the error and it reappears again, if I press OK nothing happens and the only way to end the process is to kill it.

So, how can I remove just the plugin at fault, and not the whole config dir in my home?
Some othe people seem to have the same problem (on StackOverflow): http://stackoverflow.com/questions/2782425/intellij-bad-plugin-how-to-start

Workaround:
If I delete ~/.WebIde50, the system seems to work just fine.

UPDATE: If I delete all plugin files under ~/.WebIde50/config/plugins, every file except availables.xml, the IDE starts fine.

Also after this I was able to browse the plugin repository again and I successfully installed AngularJS plugin.

Please also note I haven't used Git/Github with Idea yet, my guess is that works fine too. /UPDATE

Aditional information, content of ~/.WebIde50/config/plugins:

AceJump
angularjs-plugin.jar
assets
availables.xml
bzr4idea
ClosurePlugin.jar
Embedder_9951.jar
Heroku
idea-handlebars.jar
idea-markdown
launchpad-plugin
NUnitJS_10668.jar
Robotlegs_11138.jar
SmarterEditor_11053.jar

Errors extracted from the log:

2012-12-29 08:55:35,579 [ 308123]  ERROR - com.intellij.ide.IdeEventQueue - Error during dispatching of java.awt.event.MouseEvent[MOUSE_RELEASED,(338,97),absolute(643,542),button=1,modifiers=Button1,clickCount=1] on dialog0 
com.intellij.util.IncorrectOperationException: createComponent() returns null for: class com.intellij.openapi.actionSystem.ActionManager
        at com.intellij.openapi.components.impl.ComponentManagerImpl.getComponentFromContainer(ComponentManagerImpl.java:180)
        at com.intellij.openapi.application.impl.ApplicationImpl.getComponentFromContainer(ApplicationImpl.java:567)
        at com.intellij.openapi.components.impl.ComponentManagerImpl.getComponent(ComponentManagerImpl.java:202)
        at com.intellij.openapi.components.impl.ComponentManagerImpl.getComponent(ComponentManagerImpl.java:197)
        at com.intellij.openapi.actionSystem.ActionManager.getInstance(ActionManager.java:44)
        at com.intellij.openapi.keymap.impl.IdeMouseEventDispatcher.a(IdeMouseEventDispatcher.java:105)
        at com.intellij.openapi.keymap.impl.IdeMouseEventDispatcher.dispatchMouseEvent(IdeMouseEventDispatcher.java:202)
        at com.intellij.ide.IdeEventQueue._dispatchEvent(IdeEventQueue.java:538)

2012-12-29 08:47:43,751 [   6893]  ERROR - plication.impl.ApplicationImpl - class git4idea.GitVcs overrides final method getName.()Ljava/lang/String; 
java.lang.VerifyError: class git4idea.GitVcs overrides final method getName.()Ljava/lang/String;
        at java.lang.ClassLoader.defineClass1(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:791)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:634)
        at com.intellij.util.lang.UrlClassLoader._defineClass(UrlClassLoader.java:125)
        at com.intellij.util.lang.UrlClassLoader.defineClass(UrlClassLoader.java:121)
        at com.intellij.util.lang.UrlClassLoader._findClass(UrlClassLoader.java:97)
        at com.intellij.ide.plugins.cl.PluginClassLoader.b(PluginClassLoader.java:102)
        at com.intellij.ide.plugins.cl.PluginClassLoader.loadClass(PluginClassLoader.java:63)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:356)

Message was edited by: Bogdan Bivolaru