"Then I tried to connect to the internet. The browser started loading the page and became unresponsive with the progress bar half-way. Back and menu buttons don't work. Finally I got an " Activity Browser (in application Browser) is not responding. Force Close or Wait. "
I have also gotten this message when accessing the dictionary. I don't use the browser much so I don't see it there. I can reliably reproduce this problem by accessing the dictionary several times. Conversely, I can avoid it by not accessing the dictionary.
If you google this message, you will find that numerous "Nook" users have gotten it too. I did not find a reliable fix among "Nook" users either.