Ok new update available
Found the fog issue(100% my fault) but its been fixed. It has created another issue which I need to track down now. When exporting, the background image is being saved with a strip of the chosen transparency color in the middle, you only notice if you change the fog color.
seeing as hows its only one image you could just open it up in paint and flood fill it with your fog color to fix it but I will track it down(strangely enough does not do it when you test without exporting)
0.5 increments have been added. looks a little ugly as it now displays under the buttons partially(especially in minus figures) I will increase the box size for the next update so that the numbers can be viewed better.
I also tracked down a couple of other bugs that luckily nobody had spotted yet :P
Hope that helps out your game development.
Give me a shout if you need anything else added and when your game is finished post a link here, could be good advertising for both of us ;)