I've noticed that mine seems to get a bit "brighter" after I've read/turned several pages. That could just be a trick of the eye, I suppose.
On the occasions when I pick it up after leaving it lying around on for a while (but less than an hour, when it turns off) I've been clicking page forward 3 times and then page back 3 times to get it to refresh 6 times rapidly, that seems to loosen it up some.
