Adobe Illustrator - how to prevent the "Eraser Tool" from changing the target brushes' size?

I am running Adobe Illustrator 2014, Release 2014.0.0 18.0.0 (x64).

I'm using a custom brush with these settings:

Whenever I draw a (pressure sensitive) line using my Wacom Intuos Pen & Touch and then erase a part of that line using the Eraser Tool (SHIFT + E), the remaining parts of that line will become way thicker, almost as if I never used pressure senitivity drawing that line and just drew it using the same brush and my mouse.

Here is an example of the line before and after using the eraser tool on it:

How do I set it up so it does not change the thickness when I remove parts of the line using the Eraser?