If you mix light sources, you are destined for white balance problems. Here is what can happen. Top photo has mixed light sources, bottom does not. Using diffused lighting is good for proof coins and iridescent color coins, but you really shouldn't need to use it for standard white coins. I think if you try two direct lights of the same type at 10 & 2 at a high angle, you will like the results. You are already very close.
I have attempted to download it 4 times now and I think it's on my computor 4 times. I can't find it when I try to install it or access it. It there another name the file might be under?
When you download , do you download the application to your desktop? Makes it a heck of a lot easier to find.......