Android XML-RPC Serialization Issue

Question

I am attempting to use Android XML-RPC and for some calls I get the following exception:

W/System.err( 837): java.io.IOException: Cannot serialize java.lang.Object@43759748

It looks like it is having troubles serializing the returned data, but I cannot find much documentation on how to actually use Android XML-RPC.

The way I am using Android XML-RPC is as follows:

Object response = (Object)client.call("sales_order.list", new Object());

This one is pretty odd. I have tried setting this call up in a few different ways (using HashMaps, not passing second variable, etc) and the response I get is that sales_order.list is not a valid Method.

I have been able to login to the service using the following code:

this.sessionId = (String)client.call("login", this.apiUserName, this.apiPassword);

Does anyone have any ideas or a good resource on how to use Android XML-RPC?

Thanks