Color rendering problem - difference transparency

I see a problem how colors are rendered with CorelDraw X6 uniform difference transparency blending. The effect is very interesting for me but what I see in CorelDraw workspace is different what is expected and what I get. 

Case one

White on black as exported to file

...and as seen in my CorelDraw workspace:

Nothing special here.

Second case

Red on red, as exported to file looks like:

...and here's a zoom from my CorelDraw workspace as seen on a screen:

Notice that cyans are different, even though color picker shows exactly the same color values. Strange...

Third case

Cyan on red, as exported looks like:

Nice! As expected. But on my screen it looks like:

Reds are different. Moreover cyan appears where white is expected!

Look what color picker shows:

What is going on?

wtf.cdr