I have tried that, but that does not compile:

[error] /tmp/code/scalding/scalding-core/src/main/scala/com/twitter/scalding/Job.scala:168: type mismatch;
[error]  found   : Seq[(AnyRef, AnyRef)]
[error]  required: Seq[(AnyRef, String)]
[error]       val tempMap = MMap[AnyRef, String](config.toSeq :_*)
[error]                                                 ^
[error] /tmp/code/scalding/scalding-core/src/main/scala/com/twitter/scalding/Job.scala:169: type mismatch;
[error]  found   : java.util.Map[AnyRef,String]
[error]  required: java.util.Map[java.lang.Object,java.lang.Object]
[error] Note: String <: java.lang.Object, but Java-defined trait Map is invariant in type V.
[error] You may wish to investigate a wildcard type such as `_ <: java.lang.Object`. (SLS 3.2.10)
[error]       AppProps.addApplicationFramework(tempMap.asJava,
[error]                                                ^
[error] two errors found
[error] (scalding-core/compile:compile) Compilation failed
[error] Total time: 7 s, completed 26.07.2013 20:50:00


The tempMap has to be Map[AnyRef, AnyRef] to satisfy the method contract. 

If I change it to just that, it compiles, but fails at runtime by printing lots and lots of error messages. 

I am new to scala, so there must be something obvious, that I am still missing..