Export to transparent png

I know that X4 isn't supposed to work with Windows 10 and I have run across some minor glitches (mostly cosmetic) until now. I have a number of drawings I have done over the years and occasionally I like to post them to relevant discussion forums on the Internet (one of which I administer) . In the past (when I was on Win 7) I would export the cdr to a transparent .png. Worked fine.

But since migrating to Win 10, I can no longer get a transparent background when i export to png. White is the default background and when I choose white to be transparent, everything seems as it should be and has been. But the result is not transparent at all the white background is still there.

Is ther a work around, an updated p.ng filter or any way to get a transparent background from CorelDraw X4 on Windows 10?