Interesting, I have had exactly the same problem with my new Camry Hybrid. I'm on my 3rd starter battery and the dealer has had it in 4 times (2 times for a week) and has found nothing. Every time I have left it for 3 days or more it's stone cold dead. Dealer has given up and I'm not happy! Check out the discussion on the Camry Hybrid thread.

http://www.greenhybrid.com/discuss/s...ad.php?t=12585