ListView inside ListView (Scrolling issue)

Hello, i make a little cheat with grouping elements and put one ListView inside other ListView, everithing displaying ok, but have a little issue, when user try to scroll elements pressing to the top list view element – everithing is ok, when user press to the internal ListView and try to scroll up (from the bottom of the device to the top) apliccation don’t responce to this gesture. But if try to scroll down (from top to bottom) – everithing is ok, and one more, if start scrolling down, and then scroll up – everithing is ok too.. How know, what is the magic is here? :)