I have used keyboard shortcuts for years without trouble, but my experience with recent versions of photoshop shortcuts are nearly unbearable. Frequently when I try to switch between the brush tool and the eraser, or to the healing tool, or the stamp tool, photoshop will simply 'ding' at me with an error sound. It dings at me when I try to change the brush size. Other times, it won't ding, but it also won't change tools. It regularly seems to think I'm holding the 'alt' key and keeps opening top menus when i try to select a tool. I press escape and try again, but it's still convinced I'm using 'alt'. It gets stuck in the layer style drop-down so that as I try to nudge the image, it just changes the layer style instead. I have to press escape to get out of that. My keyboard has become an incredibly unhelpful tool in photoshop, which is the exact opposite of what it's been for years. BTW, i recently replaced my keyboard, but was having the problem before that as well. It's NOT my physical keyboard.