In this video I swap between brush and eraser tool and as you can see, nothing happens.

I'm using Macbook Pro late 2008 model (MacbookPro5,1) with Intel Core 2 Duo 2.53gHz, 4 GB RAM, NVIDIA GeForce 9400M and 9600 GT

Operating System: Mac OS 10.9.2.

Adobe Photoshop Version: 13.0.6 (13.0.6 20131025.r.54 2013/10/25:21:00:00) x64

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