Simple client-server application don't work depending on CPU

Hello, I have a simple client-server Visual c++ 6.0 Ice application running on 2 Windows XP Professional 2002 SP3 machines.

With an Intel Core2 Duo CPU, everything works fine, but with an Intel Core2 CPU the server does not work.

My slice is very simple, too:

module AVStreaming {
sequence<string> FlowSpec;
sequence<byte> Imagen;

exception FPError { string flowName; };
exception NoSuchFlow {};

interface BasicStreamCtrl {
["ami"] void setFPStatus(FlowSpec theSpec, Imagen theImage, string fpName, int deflated);

...
}

The thing is that the following server-side function:

void AVStreamingI::setFPStatus(const AVStreaming::FlowSpec& fs, const ::AVStreaming::Imagen& im, const std::string& st, ::Ice::Int deflated, const Ice::Current&)

never gains (takes) the control of the program, it is, it never executes, so I can not call fs.back().data() inside this function.

Any clue about what is happening?