Unusual Marker Image Issue

[smartcoda]

So I'm having a weird issued with a custom marker, first time I've had an issue.
The PNG image is fine, as shown here (actual file in use uploaded to imgur) but when it runs through VRS it corrupts rather badly, as shown here


Any idea as to what is causing this? The image that is corrupting is a white fill marker, all my other colours for the same marker are perfectly fine. I thought at first it was due to being a pure white colour (#FFFFFF) so I did try a ever so slightly off white colour (#FEFEFE) but to no avail.

ps, the image isn't quite true of a DC10/MD11 yet, but I don't want to put further work into making it exact if all the markers aren't going to display well, especially as most the markers are going to display as the corrupted image.

[smartcoda]

And now I've fixed it, phew. I decided to do some digging into the PNG file format, that led to me looking at the values for each pixel, and then I realized that the tool I was using to adjust the marker into the center of the image (mogrify, because I'm bulk adjusting as it's easier normally) had changed the colourspace on the white fill marker to gray+alpha instead of RGBA. It seems 2 channel PNGs are bad news. Just something to watch out for if you're as obsessed as me when it comes to custom markers