Tablet pen eraser problems (Corel Painter Essentials 5)

So I recently started using Painter Essentials 5 with my Wacom Intuos Pro, and so far I love the program. However I have run into one difficulty. Whenever I try to use my pen eraser, it doesn't' switch to the eraser tool. When I check my pen settings for the program it says that it's set to eraser, however it just won't work. I haven't run into this problem before with other programs, so I was wondering if anyone had any idea of how to fix this.