My wife and I got our Kindles in Nov '09, about a week apart. I have 19 pages of books, mostly the free or low cost ones. She has 3 pages with 1 page of samples. I study the various Kindle fora, she could care less. Today I manually updated my Kindle about 30 minutes before Amazon released the update for 2.5.2. I did not touch her Kindle, other than to turn the whisperjet on and make sure it was fully charged. I put both into sleep mode and we went to the store. When we returned - her Kindle had been updated to 2.5.3 and mine is still at 2.5.2.
As the poet said - "it just goes to show you".