Exception thrown on creation of Google App Engine Google Web Tools initial project

Question

The following log file is created when I create a GAE GWT project:

java.lang.RuntimeException: Unexpected exception
    at com.google.appengine.tools.enhancer.Enhancer.execute(Enhancer.java:59)
    at com.google.appengine.tools.enhancer.Enhance.<init>(Enhance.java:60)
    at com.google.appengine.tools.enhancer.Enhance.main(Enhance.java:41)
Caused by: java.lang.reflect.InvocationTargetException
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at com.google.appengine.tools.enhancer.Enhancer.execute(Enhancer.java:57)
    ... 2 more
Caused by: org.datanucleus.exceptions.NucleusException: Error reading manifest file "jar:file:/C:/!Dev/appengine-java-sdk-1.3.5/lib/user/orm/datanucleus-appengine-1.0.7.final.jar!/plugin.xml"
    at org.datanucleus.plugin.NonManagedPluginRegistry.registerBundle(NonManagedPluginRegistry.java:389)
    at org.datanucleus.plugin.NonManagedPluginRegistry.registerExtensions(NonManagedPluginRegistry.java:222)
    at org.datanucleus.plugin.NonManagedPluginRegistry.registerExtensionPoints(NonManagedPluginRegistry.java:153)
    at org.datanucleus.plugin.PluginManager.registerExtensionPoints(PluginManager.java:82)
    at org.datanucleus.OMFContext.<init>(OMFContext.java:160)
    at org.datanucleus.enhancer.DataNucleusEnhancer.<init>(DataNucleusEnhancer.java:172)
    at org.datanucleus.enhancer.DataNucleusEnhancer.<init>(DataNucleusEnhancer.java:150)
    at org.datanucleus.enhancer.DataNucleusEnhancer.main(DataNucleusEnhancer.java:1157)
    ... 7 more
Caused by: java.io.FileNotFoundException: C:\ (The system cannot find the path specified)
    at java.util.zip.ZipFile.open(Native Method)
    at java.util.zip.ZipFile.<init>(Unknown Source)
    at java.util.jar.JarFile.<init>(Unknown Source)
    at java.util.jar.JarFile.<init>(Unknown Source)
    at org.datanucleus.plugin.NonManagedPluginRegistry.registerBundle(NonManagedPluginRegistry.java:335)
    ... 14 more

Prefrences -> Java -> Installed JREs properly points to my JRE6 directory. I'm not sure where to look to fix this. Any suggestions as to how I might track this down?

I'm sure it's a configuration somewhere, I'm just not sure where to look. I searched all Eclipse files for C:\ but didn't come up with anything that looked like it would impact what I'm seeing.