OS X V10.7 Lion :: Printing From Outlook 2011 Stopped Working

I am working with a friend who uses Microsoft Office 2011 on an iMac running 10.7.2. He is suddenly unable to print from Outlook. Choosing Print... from the File menu or clicking a print button produces no result at all - the normal print dialogue box does not appear. Previously he could print without a problem. He has no problem printing from Word in Office 2011.

We have updated Office to 14.1.4 through Microsoft Update. We have worked through the advice in the Microsoft support document 2409305 - backing up Outlook identities, and removing Oulook Preferences as advised there. The error remains. We then created a new identity and found we could print from that. So we followed the Microsoft advice to rebuild the Outlook identity database. We still cannot print from Outlook.