Cannot print attachments from Outlook 2007

I have a user who has Outlook 2007 with Acrobat Reader XI currently and wants to print all the attachments within his emails when he prints the email itself. I have also tried Acrobat XI Standard with the same results. After a week or so he stops being able to print the attachments, then I'll stop all acrobat processes, close outlook, maybe reboot and it works again. Why does acrobat continue to freeze up?