Problems exporting a file with drop shadows to PNG

Hello all,

I am trying to export a file that has a couple of drop shadows in it. The drop shadows were created using the Stylize effect and Multiply option.

I am exporting to PNG format at 300dpi without transparency. However, the objects in front of the drop shadows are becoming transparent, and only the drop shadow is showing in the PNG file.

Here is what the file looks like in Illustrator:

And this is what the file looks like when it is exported to PNG:

Can anyone please provide a solution to this one?

Thanks!

Bron