Automatic check box selection in android custom listview

I'm new to android and building a list and the list contain installed app name with a CheckBox to chose which one to uninstall. for example, the problem is that when the list became longer than the phone screen and the scrolling is active; when i select a check box , a second one is automatically selected in the bottom of the list.

The problem is automatic checkbox selection of check boxes, plz help me.