Android :: Unwanted State Changes Of CheckBoxes In ListView

I am facing a very mysterious Problem. I am using a ListView with CheckBoxes that can be clicked to select people. The row layout is the following:

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="fill_parent" android:layout_height="wrap_content"> <CheckBox android:focusable="false" android:onClick="onSelectPerson" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center_vertical" android:layout_marginRight="5dip" android:layout_marginLeft="5dip"/> <TextView android:id="@+id/person_name" android:text="test" android:layout_width="wrap_content" android:layout_height="wrap_content" android:gravity="center_vertical" android:textSize="18dip" android:layout_marginLeft="5dip"/> </LinearLayout>

As long as the amount of rows doesen't exceed the screen size (-> no scrolling) everything works just fine. But as soon as I have more rows then the screen size (-> some rows are hidden and have to be scrolled to). I have a very mysterious phenomenon: If I check the top row and scroll down some of the previously hidden rows are randomly checked too. If I scroll up again, again some of the before hidden rows are randomly vhecked (the CheckBox I clicked in first place may or may not still be checked). Also the registered onSelectPerson callback is only called for the CheckBoxes I really click. The other CheckBoxes just change their state to "checked" without calling the callback method. I have the same phenomenom on the Archos IT 5 and the Nexus One. This must have something to do with the ListView implementation but I can't quite figure out what the problem is.