If you are actaully trying to share the "slice" itself and not the object within a standard layer, you must first create a web sub layer in the within the web lay section of the Layers panel. Place the slice(s) you want to share in that sublayer, then you will be able to share the sublayer to other web layers in your design.
Understand there is a difference between Pages and States. A great resource for learning more about this is Dave Hogue's article on the Fireworks Dev Center:
Thanks so much Jim for your help. I created the sub-layer of the web layer for the problem page and can now share to other pages.
However, the layer that was originally working is directly in the web layer of the page it is on and it allowed me to share with other pages without putting it in a sub-layer.
Also, I am finding that after exporting to a PDF, the slice is not shared to other pages as one would expect.
I can't suggest much more without seeing the actual Fireworks PNG file. If possible please share it here or email me offline.
Thanks again for your time and help. You can find the file here:
On page 1 are the two slices giving me trouble carrying over to other pages.
There is one slice on page 2 which was the one that didn't give me any trouble selecting "share layer to pages" even though it wasn't in a sub-layer of the web-layer.
I think I may have just figured this out. I needed to put the slices on the master page. At least that's what I did and it is now working fine.