Hi Mario,
To answer your question, let me give you a brief comparison of the Multisim/Ultiboard design environments in terms of handling multi-pages/hierarchy:
Multisim provides a hierarchical environment that allows a design to be spread across multiple pages (in addition to allowing the insertion of subcircuits and hierarchical blocks). Ultiboard, however, is a 'flat' environment that is not hierarchical since it is the actual layout of the PCB. When designs from Multisim are transferred to Ultiboard, they are essentially 'flattened'. So if you have a multi-page design (such as your project which is spread over several schematic pages), Ultiboard essentially does not care about this - it only cares about the components in the design at large regardless if the nets are connected across multiple pages.
If you are not seeing the components on the other pages being transferred, perhaps the other pages are part of a separate project? To add a page to the design itself you need to go to Place > Multi-Page.
Hope that helps, and if you still are having trouble, feel free to post an example circuit and I can take a look.
Natasha
