I have a file that consists of various fountain Fills. When I publish to pdf and choose prepress preset or any other preset only one of the fountain fills is retained imported back to cd for verification. The other Fountain Fills are made up of a thousand shapes all of different "stepped colors" to make up the fountain fill.
Indeed, checking in Acrobat does help. It would list the individual pieces making up your gradient.I don't have X7 installed anymore, and just removed X8 recently. But 2017 exports any of these settings as a single object with a smooth shade fill.
You can use a plugin such as Enfocus Pitstop for view wireframe on Acrobat.
And not, that was not an issue os CorelDRAW, only about the option choosed when export to PDF. Try using compatibility with Acrobat 9.0
There were improvements to fountain fill support from X7
Myron, can you attach a file sample (cdr and pdf) for test?
Drop box link