Further anecdotal evidence: The only time my Kindle has ever crashed was sometime before/during/after a 9 hour flight. I didn't try to use it during the flight but used it earlier in the day, so it could of been either the x-ray or the flight (or coincidence) that crashed it. It was a hard crash that required plugging it into a computer to reset it; just holding the power-switch did nothing.

For the record: it was Kindle3 (non-3G) in an official leather book-style case (the one without the light) and the wireless was off (I always leave it off for battery reasons).

Article says the cost is 138000 yen (~1750 USD). So not cheap!