mmh. Pretty strange that. It is possible that your device's flash is broken.
Or you could have corrupted images. (more likely I think)
At least there's no "downgrade disallowed" message so your images are probably the correct version.

What you could do, is to download ubiboot kernel, and try to boot with that to maintanance mode. Then you'd find out if your flash is OK and partitionable.

• download http://www.swagman.org/juice/ubiboot...3.5_301013.tar
• extract the file zImage_2.6.32.54-ubiboot-02_301013
• use flasher to jumpstart that on your device: "sudo flasher -k zImage_2.6.32.54-ubiboot-02_301013 -l -b"
• connect USB cable to powered-off N9
• Wait for the filesystem to export to Linux

You do need linux with that, windows is pretty much useless.