@ixtab: Well, after a quick look at the package, it at least unearthed a stupid bug in KindleTool, but I'm not sure it's actually harmful since everything runs as root... (When creating a tarball, directories end up with broken permission: they're not searchable).
Will continue looking into it...
EDIT: Not sure what's the $PWD during the update process when the install script is in a subdirectory, and since it's using relative paths, I'm not quite sure it's actually finding the kernel & partition dumps... (Try repacking it with -C ?) [I'm still confused, like you, as to why that wouldn't completely wreck the FS, though. But I'm not familiar with dd, and even less with busybox's implementation, so, there may be some *nix magic at work here ^^]
Last edited by NiLuJe; 10-31-2012 at 08:40 AM.