Pen unreliable and colour picker buggy

I am a very ammy user, just upgraded to animate 3 on my mac and am EXTREMELY disappointed with this product. Just doing really really basic stuff and finding software frustratingly buggy. At this stage I am using my track pad to draw (horrible as that is) and am having some basic issues that is destroying my enthusiasm to create my product.

1 - Drawing with the pen sometimes works and sometimes doesn’t. I will hold mouse button down and draw and nothing will happen, repeat this two or three times with no success, then suddenly it will work.
2 - sometimes after drawing a line a small blue dot (I have dubbed the dot of death) will appear at the end of the line. Cant do anything till I click the blue dot and then my line disappears.
3 - when I select a colour to duplicate using the colour dropper it just gives me white or black, nothing resembling the correct colour. Once again, it HAS worked before, but doesn’t seem to now.

Using OSX 10.9.4 with ample power in my computer. For something costing as much as this is I am absolutely pulling my hair out with frustration as am not trying to do anything complicated at this stage, just drawing.

From your description it sounds as though your system is using an under-powered graphic card.What is the specific model?