.NET to apache axis interoperability problem

I'm trying to write a .net client to consume a webservice created with
apache axis.
I was able to consume services that return a single value, such as long or
string types. However, the target webservice returns a complex type
consiting of an array of objects/structurses and several value types.

.NET 1.1 / Visual Studio 2003 interprets the WSDL correctly (it seems)
creating the proxy objects. However, when I call the service .NET seems
not to be able to de-serialize the returned document into the object
hierarchy. All references to nested objects / arrays of objects are null.
(without an error message being generated).

Has anyone experienced the same problem or implemented axis to .NET
integration with complex types?

regards

Erwin Richard