Apparently, there is an audio library issue that freezes Samsung phones when the screen locks. They are working on it.
http://support.ludei.com/hc/communities ... ock-screen
From Jon (Ludei Support):
"
Ok, good news! After updating the audio library to the latest version (which has quite a few fixes), the hang no longer happens in your game <img src="{SMILIES_PATH}/icon_e_smile.gif" alt=":)" title="Smile">
We'll go through our usual round of testing, and hopefully this fix will make it to production during the next 2-3 weeks.
Thanks again for reporting!
"