Error de Datebox useFocus en dispositivos iOS

I am using calendar mode of Datebox con mi jQuery Mobile project, everything works fine but when I use useFocus to open calendar wherever I click on the input field, it isn't stable in iPhone (or other iOS devices), sometimes it opens and many times it acts like crashing. But the same is working good in Desktop browsers, when I use without useFocus it works right in mobile devices also, I see same stability issue in sitio web del complemento demos too. How can we correct this issue?