Dragging guides or moving the mouse over the ruler is adding "dirt" to the ruler.

Whenever I drag a guide out, wherever the guide slides along the ruler, the ruler ends up with little black marks along the ruler which makes it difficult to see the actual marks that the ruler has. Any fix for this? Same thing if I just move the mouse around. When you move the mouse, both the top and left ruler follow the cursor with a little line along the ruler so you can see where your mouse is on the page. That little line adds "junk" to the ruler as well. It's only a couple pixels tall of junk, but that makes seeing the 1/8" marks on the ruler difficult to see. Using current CC on OS X.