I made a rather complex image of a moutain viewed from afar, and, to create a proper paralaxing effect, I need to expand the image I drew lengthwise. The problem is that when I have expanded it to the desired length and proceed to deselect the layer, large swaths of specific colors disappear.
What I have tried:
Converting to symbol & movie clip
Replacing true white with a light blue
Selecting other layers instead of hitting the deselect shortcut
Original MountainMountain expanded and subsequently deselected
I've had this same problem myself quite frequently when making very complex vector art. Usually I'm able to skirt around it by grouping the drawing or converting it to a symbol before resizing, but it sounds like you've already tried that with no success.
My only other suggestion would be to go to Modify>Shape>Optimize and set the strength as high as you can without compromising your artwork. I've had that solve the problem in the past.