title: iPython notebook won't open some files
body: <p>I have a git folder with several ipython notebook files in it. I've just got a new comp and installed ipython. When I open some files, it works fine, others, however, display this error:
  Error loading notebook, bad request.</p>
  
  <p>The log looks like:</p>
  
  <p>2014-07-16 00:20:11.523 [NotebookApp] WARNING | Unreadable Notebook: /nas-6000/wclab/Ahmed/Notebook/01 - Boundary Layer.ipynb [Errno 5] Input/output error</p>
  
  <p>WARNING:tornado.access:400 GET /api/notebooks/01%20-%20Boundary%20Layer.ipynb?_=1405434011080 (127.0.0.1) 3.00ms referer=linktofile</p>
  
  <p>The read/write and owner permissions are the same for each of the files. The files open fine on my other computers, it's just this new one. Any ideas?</p>
  
  <p>Cheers,
  James</p>