Thanks for the help everyone!
This is the content of kindle root folder just before the update, with all the *.bin files from "...\Duokan_0_5_13_8914__2011_04_08_english\升级包\k3 升级包"
I have a Kindle 3 Wifi US (3.1) ... how do I determine the necessary *.bin file?
As a side note: Even after an unsuccessful update no *.bin files remain in the root folder.
And I always get the error U007 during the update process and no errors during the reboot.
regards.
bearmann
PS: And I'm quite sure, that it's NOT bearwoman.