Using NuSOAP and gSOAP, but not clean yet...

I've been playing around with NuSOAP as a PHP based SOAP server and
client. Works great!

Now I'm trying to write (using gSOAP) a simple C/C++ based client to
test against my simple SOAP server. Not so easy.

My client forms the request nicely, and I see with my packet sniffer
that the SOAP server is producing the expected response message, but
all I can get my client to do is return a NULL pointer (at least I
don't have any errors!).

And since I'm a raw SOAP newbie, I haven't got much of an idea why
this isn't working (am I in some kind of namespace trouble?).

So I'm wondering: does anyone here have any experience with a *free*
C/C++ SOAP client that works as nicely with NuSOAP as NuSOAP works
with itself? Or better yet, any tips for configuring a gSOAP client
to work with a NuSOAP server?

TIA

Eric