autostart not working in Android Browser 4.0

@ css code for pages: class (.) not id (#)! (the code above works for posts only)

.page-id-123 .flowplayer {
   background: url(https://www.mydomain.de/wp-content/uploads/2014/03/whatever-splash.jpg) 0 0 no-repeat !important;
   background-size: 200%;
   -webkit-transition: background 1s .5s;
   -moz-transition: background 1s .5s;
}
.page-id-123 .flowplayer.is-poster {
   background-size: 100%;
}