I just tried some experimentation and I found that swiping on Slide to Answer (under MagicJack, “Incoming call from…”) on the homescreen answers the call (after activating the Password input screen, which requires first entering the password) only if the magicJack Landline is taken off the hook. If the landline is plugged in and the user attempts to answer the call from his iPhone, for some reason magicJack gets confused and does not recognize that the user has attempted to answer the call on the iPhone and the landline continues to ring. Taking the landline off of the hook addresses this issue.