Description of problem: udev sets its magic string in the first 512 bytes of the partition. This is dangerous and error-prone, because other things like boot sectors and BSD disk labels tend to live in the first 512 byte sector. Additional info: Please report to upstream, full text available at http://article.gmane.org/gmane.comp.file-systems.ext4/2316/
"udev sets its magic string in the first 512 bytes" s/sets/gets/
That's nothing new. Guessing filesystems by magic bytes on the disk is by definition unsafe. _All_ filesystem formatters are required to wipe out _all_ existing signatures before applying a new signature. Even then, it's not entirely safe to probe, but we obviously have no alternatives. Shuffling the probing order around will only switch the systems where such problems occur. From my standpoint, you can close this "bug". Thanks!
Closing based on comment #2. All formatters need to wipe out all signatures