Thanks. According to the log, ubiboot found the kernel each time OK (both Harmattan boot and Nemo boot go correctly up to loading phase)
As it is, unfortunately ubiboot cannot detect problems that happen after loading the kernel, for example if there are problems loading the modules or running init.


No, if the kernel ID string (release, like what you see with "uname -r" command) is different in your new and old kernel, then you do not need to delete old modules.
When the kernel boots, it will try to load the modules from the directory named like release number, so the original N9 kernel will try to load from /lib/modules/2.6.32.54-dfl61-20121301, and the kernel-plus from /lib/modules/2.6.32.61-plus.
This way you can have multiple kernels to boot, each one will know to load its modules from its own module directory.