GWTUpload - New dependency breaks RPC calls?

Question

Before, I had the following dependency in my POM file:

<dependency>
        <groupId>gwtupload.server.gae</groupId>
        <artifactId>gwtupload-gae</artifactId>
        <version>0.6.6</version>
</dependency>

The groupId seem to be changed to com.googlecode.gwtupload. If I change the dependency to:

<dependency>
        <groupId>com.googlecode.gwtupload</groupId>
        <artifactId>gwtupload-gae</artifactId>
        <version>0.6.6</version>
</dependency>

Or to:

<dependency>
        <groupId>com.googlecode.gwtupload</groupId>
        <artifactId>gwtupload-gae</artifactId>
        <version>1.0.1</version>
</dependency>

All my RPC calls fail with the message:

[ERROR] A RPC method threw an error: com.google.gwt.user.client.rpc.StatusCodeException: 500 Internal Server Error The call failed on the server; see server log for details
        com.google.gwt.user.client.rpc.StatusCodeException: 500 Internal Server Error The call failed on the server; see server log for details
            at com.google.gwt.user.client.rpc.impl.RequestCallbackAdapter.onResponseReceived(RequestCallbackAdapter.java:209)
            at com.google.gwt.http.client.Request.fireOnResponseReceived(Request.java:259)
            at com.google.gwt.http.client.RequestBuilder$1.onReadyStateChange(RequestBuilder.java:412)
            at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
            at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
            at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
            at java.lang.reflect.Method.invoke(Method.java:606)
            at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
            at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
            at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
            at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessagesWhileWaitingForReturn(BrowserChannelServer.java:338)
            at com.google.gwt.dev.shell.BrowserChannelServer.invokeJavascript(BrowserChannelServer.java:219)
            at com.google.gwt.dev.shell.ModuleSpaceOOPHM.doInvoke(ModuleSpaceOOPHM.java:136)
            at com.google.gwt.dev.shell.ModuleSpace.invokeNative(ModuleSpace.java:576)
            at com.google.gwt.dev.shell.ModuleSpace.invokeNativeObject(ModuleSpace.java:284)
            at com.google.gwt.dev.shell.JavaScriptHost.invokeNativeObject(JavaScriptHost.java:91)
            at com.google.gwt.core.client.impl.Impl.apply(Impl.java)
            at com.google.gwt.core.client.impl.Impl.entry0(Impl.java:356)
            at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
            at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
            at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
            at java.lang.reflect.Method.invoke(Method.java:606)
            at com.google.gwt.dev.shell.MethodAdaptor.invoke(MethodAdaptor.java:103)
            at com.google.gwt.dev.shell.MethodDispatch.invoke(MethodDispatch.java:71)
            at com.google.gwt.dev.shell.OophmSessionHandler.invoke(OophmSessionHandler.java:172)
            at com.google.gwt.dev.shell.BrowserChannelServer.reactToMessages(BrowserChannelServer.java:293)
            at com.google.gwt.dev.shell.BrowserChannelServer.processConnection(BrowserChannelServer.java:547)
            at com.google.gwt.dev.shell.BrowserChannelServer.run(BrowserChannelServer.java:364)
            at java.lang.Thread.run(Thread.java:744)

Is there a solution for that problem?