Header always shows in android-pulltorefresh when customize

I was trying to customize android-pulltorefresh library developed by Johan Nilson. I wanna use my own adapter rather than a String array. I was able to complete almost every thing but the pull to refresh header is always visible. (see the image) I want it to visible only when I pull the listview like it does with the demo app. I compared my code with the demo but I couldn't find any difference between them which effect layout.

Thanks in advance !