when i click thumbnail, it open new windows and show large size photo. last time i use old version 1.2 no problems. update to 2.2 face this problem

www.ninesquare.com.my/index.php?option=com_content&view=article&id=12&Itemid=8

This is due to conflict, either with a script of your template or with another extension.
I suggest you using SIG PRO which has many different pop ups to select from in order to avoid such issues.