You must remember that your ImageView
inside your convertView
(list element) is being reused all the time. In short you don't create a new convertView
every time a new view shows up from the ListView
you actually just reuse the last element that scrolled out.
So in your case lets say you have a list where 3 items are visible at any time. When you clear item 1 you also clear item 4 and item 7 etc. etc.
I can't point to the exact point where this issue bites you but based on what you describe I'm almost certain this is the issue.