Duplicate images result from how they are loaded. A drag from the gallery into 2 distinct panels should be considered a load from disc in the next section.

If you drag identical images between 2 panels (either Shift, Ctrl, or Alt drag - I forget which copies icons but keyboard shortcuts in F1 Help will tell you), you have one copy as the software keeps a reference count on the images. If you load the same image from from disc into 2 panels (using button properties) you have 2 copies. Into 3 panels, 3 copies, etc...

Any duplication results in an increase in size.

As stated earlier, please decompile your CCF using CCF Tools to see just how bad the duplication is. If you want to solve your problem, this is the only way. Once you find duplication, simply eliminate duplicate bitmaps and their references (once you open the .csf file in a text editor, you will see what I mean).