Hi, my problem for particle drawing was solved simply by double clicking on the drawing tool and by selecting a suitable number of pixels. QWhat had happened, apparently, is that I had previously double clicked on the drawing tool and then exited without setting the number of pixels. This automatically causes the number of pixels to be so high that you actually can't see the drawing tool anymore on your picture, even if it's still working (if you check on the editor, each time you use the drawing tool, it adds a bunch of particles, even if you don't see them on screen).
It works the same with the dividing tools, but I'm not sure that it can solve your problem with the maxima drawing. In my case I use 1 px for the dividing tools and 10-20 px for the drawing tool.
Hope it was helpful.