error running scala example

[cocodrino]

hi...I try to run the echo example (EchoServer.scala) but I get this error:

   Failed in deploying verticle 

java.lang.ClassNotFoundException: echo.scala
at org.vertx.java.platform.impl.ModuleClassLoader.loadFromModule(ModuleClassLoader.java:127)
at org.vertx.java.platform.impl.ModuleClassLoader.loadClass(ModuleClassLoader.java:108)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at org.vertx.java.platform.impl.java.JavaVerticleFactory.createVerticle(JavaVerticleFactory.java:55)
at org.vertx.java.platform.impl.DefaultPlatformManager$21.run(DefaultPlatformManager.java:1723)
at org.vertx.java.core.impl.DefaultContext$3.run(DefaultContext.java:175)
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:370)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:353)
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:116)
at java.lang.Thread.run(Thread.java:744)

Failed in deploying verticle
java.lang.ClassNotFoundException: echo.scala
at org.vertx.java.platform.impl.ModuleClassLoader.loadFromModule(ModuleClassLoader.java:127)
at org.vertx.java.platform.impl.ModuleClassLoader.loadClass(ModuleClassLoader.java:108)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at org.vertx.java.platform.impl.java.JavaVerticleFactory.createVerticle(JavaVerticleFactory.java:55)
at org.vertx.java.platform.impl.DefaultPlatformManager$21.run(DefaultPlatformManager.java:1723)
at org.vertx.java.core.impl.DefaultContext$3.run(DefaultContext.java:175)
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:370)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:353)
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:116)
at java.lang.Thread.run(Thread.java:744)

this code is pretty weird: no imports, no class declared...personally I would feel more confortable writting this in my ide and using sbt for compile and run, is it possible?...I did a try

   import org.vertx.scala.core.net.NetSocket

  import org.vertx.scala.core.streams.Pump

  import org.vertx.scala.platform.Verticle


  object Main extends App with Verticle {
        vertx.createNetServer().connectHandler {
              s: NetSocket =>
                    Pump.createPump(s, s).start()
        }.listen(1234)
   }

but I get tjhe same error....if I try compile it with sbt (NOT RUNNING DIRECTLY WIT VERTX) I get

   info] Compiling 1 Scala source to /home/yo/Downloads/proj/scalavrtx/scalavtx/target   /scala-2.10/classes...
   [warn] Class io.netty.buffer.ByteBuf not found - continuing with a stub.
   [error] error while loading Buffer, class file '/home/yo/Downloads/proj/scalavrtx/scalavtx/lib/vertx-core-2.1RC3.jar(org/vertx/java/core/buffer/Buffer.class)' is broken
   [error] (class java.lang.NullPointerException/)
   [warn] one warning found
   [error] one error found
   [error] (compile:compile) Compilation failed
   [error] Total time: 3 s, completed Jun 13, 2014 8:30:40 PM

I try the javascript example and run perfectly...for the scala compiled example I copy the vertx jar inside my lib (as not managed dependency) and I add the scala version to my sbt file

   libraryDependencies += "io.vertx" % "lang-scala" % "latest.milestone" 

thanks!!