random checkbox getting checked when scrolling down the list view

I'm trying to implement checkbox with OnClickListener. the examples available are all on Oncheckedchange listener.

Once i select one checkbox, and i scroll down the list view, random checkbox are getting checked. no idea why. please help.

 holder.checkbox.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                    CheckBox checkbox = (CheckBox) v;
                    ClaimList claimList = (ClaimList) checkbox.getTag();
                    claimList.setChecked(checkbox.isChecked());
                }

thanks in advance.