After problem with update from 18/04/13, I reinstalled a backup from 15/04. It worded fine.
Today (19/04) I tried an update: a warning about instabilities was daisplayed. I sarted the update anyway.
After reboot a big ERROR was displayed on the box diaplay. The only way to get control again was to reflash with an older
image using Dreamup serial.
What I will try is to tranfer the new image (19/04) to the box instead of an update to see if the build is corrupt,
or if something wrong in the update process.