Trying to set up iPad with an email account specifically for it. Wanted to have a user name of iPad-XXX & XXXX and iPad-XXX&XXXX (no spaces) where the XXXX are names but get the "Username is not available" with no further explantion. It will accept iPad-XXXX. If logged in under that account and try to change the username then get "An error occurred while updating your username." without further explanation. Ditto if signed in under primary account and change the secondary account noted. Is there some naming convention violation Comcast doesn't bother telling you about? Some explanation of the error messages would also help.