Some courses on Blackboard (e.g. geog 106) have PDFs which display a message “PDF aloud” when opened. When this displays the PDF can’t be printed or closed. I have reported this problem to Gregor Ronald. It is something to do with the way the document has been loaded onto Blackboard. The Loft office advise to open Adobe Reader separately (not in the Web Browser), save the pdf from Blackboard and then open it in Adobe Reader.