My book crashed

GRRRRR. Kindle stalled 60% of the way through The Dervish House, after gradually getting slower -- appreciable lag between pages. I've plugged it in and it's finally started up again, but I am extremely unimpressed.

Hmm, it seems to have marked the entire chapter as highlighted, and when I try to delete the highlight it hangs again.

Any suggestions, anecdotes, commiserations?

(Yes, I know I can read the book on my laptop, or even -- for that retro feel -- go and nab bugshaw's dead-tree copy. Not the point.)