Drag and drop transparent sections showing pink???

Greetings,

I'm wondering if anyone else has experienced this and has a solution.

I had  2 shapes and text box grouped to form an object. I did this 4 times on a page and then made it a drag and drop. When the answers were randomized they were showing up goofy. SO - I brought screen grabs of each image into Snagit and altered them to be identical in size and shape. As part of this process I needed to erase a corner of the images so they would align visually with my drag and drop. When I brought the new shapes in they look/function PERFECTLY with the randomizing. No more goofy placement. HOWEVER - now the areas of the image that are transparent are showing a pink color in the preview and publish. I have no idea how to get rid of this AND it only affects the objects when they are assigned as part of the drag and drop. If I deactivate them as an answer for the drag and drop and leave them on the screen then preview/publish the pink is not there. Anyone? 

Thanks!

_Gregory Lucas