This is now a working version for this. Apparently setImage is picky about being called in the gallery. I had to create a GreenfootImage of each of the PNG files and call setImage with that rather than a String of the filename.
Fixed the bug causing calculator to give wrong result for 6+6*6-6-6*6+6. Was actually a very simple fix that I had overlooked during testing. Thanks for looking.
2008/12/1
2008/12/2
2008/12/2