In Fireworks 4, button symbols are placed on unshared layers; in Fireworks 3 they are placed on shared layers. Multi-state button symbols located on a non-shared layer in Fireworks 3 will not display the changes between the states. Consequently, when Fireworks 3 opens a Fireworks 4 PNG file containing multi-state buttons, the buttons are placed on a non-shared layer and they will not display the changes across the states.
If the multi-state buttons are not contained within a symbol, you can open the button or buttons in the Button Editor in Fireworks 3 to cause them to work again. Part 1 below outlines the steps for causing these multi-state Fireworks 4 buttons to work properly in Fireworks 3.
If, however, the Fireworks 4 buttons are contained within a symbol (as in the case of a nav bar symbol), additional steps will be necessary to make the buttons within the symbol function properly in Fireworks 3.
For more details about Fireworks buttons, see Using the Button Editor (TechNote 14302). Building a Nav Bar in Fireworks 3 (TechNote 14306) describes the process of creating a nav bar symbol.