WebService - Deserialization Fails

Hello!

When testing my Java Class based WebService with the web servie navigator, I get an error message:

"Deserializing fails. Nested message: XML Deserialization Error. Result class [myClass] does not have property [somePropertyName] of type [aTypeName]. It is required to load XML."

I found some hints pointing to Java as well as to SAP NetWeaver problems, but none of these shed any light on the problem. The class "myClass" does have a public property "somePropertyName" with type "aTypeName", the class does have an empty constructor without parameters, getter and setter methods are available for this property and there are no underscores anywhere around the whole webservice. Any hints ?