PixMapShape on Windows OS

I am using a PixMapShape to draw a Picture (No Alpha, 32 bit depth with a mask) into the Graphics of another picture that consists of black and white areas. When the PixMapShape is rotated (using its Rotation property) any white in the PixMapShape becomes transparent (and thus the underlying picture I am drawing on top off shows through). If I do not rotate the PixMapShape, white appears as white (the desired effect) when drawn onto the underlying picture. On Mac OS X, I have not been having any issues, all draws as expected. I am running Xojo 2016 r1.1 and have tried it in 2016 R3 with the same results. Anyone else come across this ?

have you tried replacing “pure white” (&cFFFFFF) with “off white” (&cFEFEFE)?
the “eye” can’t tell the difference, but the computer will treat them differently