Hi,
Unfortunately, there can be only one main window with contents per smartform... What the smartform composer run-time does now on page CUADRO_PRECIOS is: take over the attributes like positioning of %WINDOW33 into MAIN, but still continuing to process the logic of MAIN. The logic in %WINDOW33 will never be executed...
Just move the page breaks to appropriate places of MAIN - then it should work, I believe.
cheers
Janis