mine just froze again while reading my news feed from calibre. Having said that I had read one sample, then 5 news feeds, so it may just have been overloaded with jumping from one thing to another, into the dictionary and out, plus downloading feeds in-between. In this instance I also got the slow page turns for a while before it froze, so I wasn't surprised.
Rebooted now and all is well
for now.........still loving this thing!