Using AR v5.1 with W98. I receive these two pop-ups should I want to read a pdf file while using IE v6.0: 'Acrobat plug-in An internal error has occurred. Could not find Acrobat external window handler.' While using AR v4.0 I never had this problem, AR automatically launched and displayed the document on the screen. What am I missing out or should I just rather use Foxit?