DrawPlus X4: Dot changing into a triangle after printing

Recently I stumbled across a problem which I cannot solve save through a workaround:
When I am using a (little)dot in a graphic and when printing this graphic as .dpp file, the dot changes into a (little) triangle.
Then I use a this workaround:
To print the dot as a dot, I export the .dpp file to a .png file and via PhotoPlusX4 print the graphic.
I am certainly doing something wrong or forget something. Can somebody give me a advice please?
Joe.