Qole, Thanks for this quick fix,
It works nicely now.

But I think you had two different issues:

• Detecting image change when it wasn't the case: this one is fixed
• Leaving the device in an inconsistent state when changing image (i.e. calling closechroot from ezchroot): i've not checked this one because i've got only one image.

And don't worry, i'll continue to use beta version (stable software is boring )