[delphin]

e-ink displays are actually a kind of nano-technology where microscopic e-ink pigment particles get yanked around in a semi-fluid medium.

So e-ink displays are dealing with physical movements on a microscopic level, not just moving electrons around at nearly the speed of light.

The response of the e-ink pigments is effected by temperature, so the electronic driver circuits have to compensate by slowing down the screen changes when it's cooler, in order to allow the pigment capsules time to fully respond.

As you hold the reader in your hand, it warms up and the response time improves.

Sometimes when the temperature changes quickly, it can't adjust quickly enough, and the pigments do NOT have time to respond fully during a screen change, then you get 'ghosting'.

So slight changes in update speed, and occasional slight ghosting, are normal, and not something that you should be overly concerned about unless you compare your reader side by side with someone else's and find that yours is noticeably worse.