In LDD version 4.3.10 I have found the four paint tool buttons to be missing. I searched online and haven't found anyone else with the same question, and the user's manual was no help. Then just playing around with LDD I noticed that if I open a free build in Extended Mode, the buttons are there, so then I have to import a model in order to use them. This is fine, but if anyone knows why the buttons would be missing in the first place, I'd appreciate hearing from them. Thanks!