Listview with checkbox bug android

I have custom list view with checkbox, when I executed in my small mobile phone, if list view already had 5 items, then when I checked item 1, then item 5 will be checked also, if I checked item 5 then item 1 will be checked also, it happened with item (2-6,3-7,4-8, etc).

But if I had 4 items in my listview, it wont be happened. Here my listview adapter :

http://ift.tt/2dQEBtI

Could you help me to solve my bug ? Thanks in advance