I have a multi-locale site set up with the different locales in different domains

• phoseon.craft.dev - English site
• phoseon.it.craft.dev - Italian site

etc.

I am having problems getting Live Preview to work with a locale other than English.

The page I am trying to get this to work on, test-single, is a single, with a template that just displays the title (so no complexity there).

When I try to use Live Preview in a locale other than English, I get this error in the console:

Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at http://phoseon.it.craft.dev/. This can be fixed by moving the resource to the same domain or enabling CORS.

And no Live Preview, just a white screen.

Based on this answer I added this to .htaccess for http://phoseon.it.craft.dev

Header add Access-Control-Allow-Origin "http://phoseon.craft.dev"

And now I see these requests, and still a white screen for the Live Preview:

POST http://phoseon.it/craft.dev/test-single 302 Found
  Request Headers:
    Accept  */*
    Accept-Encoding gzip, deflate
    Accept-Language en-US,en;q=0.5
    Content-Length  198
    Content-Type  application/x-www-form-urlencoded; charset=UTF-8
    Host  phoseon.it.craft.dev
    Origin  http://phoseon.craft.dev
    Referer http://phoseon.craft.dev/admin/entries/testSingle/1742-testsingle/it_it
    User-Agent  Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:35.0) Gecko/20100101 Firefox/35.0
  Response Headers:
    Access-Control-Allow-Orig...  http://phoseon.craft.dev
    Cache-Control no-store, no-cache, must-revalidate, post-check=0, pre-check=0
    Connection  Keep-Alive
    Content-Encoding  gzip
    Content-Length  2346
    Content-Type  text/html
    Date  Mon, 16 Feb 2015 20:38:14 GMT
    Expires Thu, 19 Nov 1981 08:52:00 GMT
    Keep-Alive  timeout=5, max=100
    Location  http://phoseon.it.craft.dev/login
    Pragma  no-cache
    Server  Apache/2.2.26 (Unix) DAV/2 PHP/5.4.30 mod_ssl/2.2.26 OpenSSL/0.9.8zc
    Set-Cookie  CraftSessionId=gtm75r2a9it49820uueam9hpe2; path=/; HttpOnly
    Vary  User-Agent,Accept-Encoding
    X-Powered-By  PHP/5.4.30

  And the response is the site's 404 page

GET http://phoseon.it.craft.dev/login 404 Not Found
  Request Headers:
    Accept  */*
    Accept-Encoding gzip, deflate
    Accept-Language en-US,en;q=0.5
    Content-Type  application/x-www-form-urlencoded; charset=UTF-8
    Host  phoseon.it.craft.dev
    Origin  http://phoseon.craft.dev
    Referer http://phoseon.craft.dev/admin/entries/testSingle/1742-testsingle/it_it
    User-Agent  Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:35.0) Gecko/20100101 Firefox/35.0
  Response Headers:
    Access-Control-Allow-Orig...  http://phoseon.craft.dev
    Cache-Control no-store, no-cache, must-revalidate, post-check=0, pre-check=0
    Connection  close
    Content-Encoding  gzip
    Content-Length  42163
    Content-Type  text/html; charset=utf-8
    Date  Mon, 16 Feb 2015 20:38:14 GMT
    Expires Thu, 19 Nov 1981 08:52:00 GMT
    Pragma  no-cache
    Server  Apache/2.2.26 (Unix) DAV/2 PHP/5.4.30 mod_ssl/2.2.26 OpenSSL/0.9.8zc
    Set-Cookie  CraftSessionId=isldd40afpu41mr9as659f6rs7; path=/; HttpOnly
    Vary  User-Agent,Accept-Encoding
    X-Powered-By  PHP/5.4.30
    charset utf-8

  And the response is agin the site's 404 page

Anyone else encountered this? Know what's going on? Recommended fixes?