I have created an xlsx file in Skydrive from my PC, when I go into Skydrive on my Nokia Lumia 800, I do see the file.
After clicking on it, the window changes to the web and it tries loading,  I now get the message:
"Can't download
You don't have permission to download this file. For help, try contacting the person who manages this site."

When reviewing the share permissions, I see the file is set to "Shared" but it is to 2 old email addresses of mine (I migrated these to an "@live.com.au" address).
I cannot find where to change the permissions. Sending an email link to myself does nothing.