I'm using SPS v2.0. I created a site and two web part pages for the
site. I then created an assembly with two classes. Class
ParmOutProvider implements the IParametersOutProvider interface.
Class ParmOutConsumer implements the IParametersOutConsumer
interface. If I add both web parts to the same web part page I can
connect them using FrontPage 2003. If I add the ParmOutProvider web
part on one web part page and the ParmOutConsumer on a different web
part page I cannot connect them. When I use FrontPage to specify a
different site it tells me there aren't any web parts on the page
that allow connections.

In both classes I call RegisterInterface with the
allowCrossPageConnection set to true.