CorelDraw X7 export to PNG not using specified pixel size

I create a graphic in CorelDraw X7.  I export it to a PNG.  In the export parameters I select a width of 324 pixels.  The resulting image is 323 pixels.  How can I tell it that I want exactly 384 pixels?

I was frustrated with similar problems many years ago (Corel Draw 4), but the problem was solved long ago.  Specifically, I don't have this problem in version X3.

 

Thanks