Why is the paint bucket tool so buggy?

I select the paint bucket tool, choose a colour, and when I go to colour in my drawing, it paints the wrong colour. The right colour is displayed on the tool bar, but it's the wrong colour on canvas. I reselect the colour and try again, and it does a different colour, still not the right one as displayed on the tool bar. So I then have to click on the coloured area on my canvas, then select the colour on the pallet to finally get the right colour. I never had this problem with Flash. How do I get it to only select the colour I want every time?