Well after saying that I never accidentally highlighted a word rather than turn the page, of course it had to happen to me today
. I was in a totally different position and holding the reader with my left hand and using my left thumb to flip the pages. Being right-handed, the left thumb apparently doesn't operate as smoothly and sure enough, I more like twitched against the screen once and highlighted a word and had to laugh at myself over it. Plus the right-to-left movement meant starting on text and not in the margin like I do with my right thumb.
But I love how sensitive the touch screen is, even with those once-in-awhile goofs.
But I agree a cover like the official Sony cover might help you out and give you more room, especially if you get the one with the light inside. If you can pick it up locally and be sure you can return it if you hate it, you would have a good 2-4 weeks to test it out then (depending on your store's return policy).