This is a known limitation of Citrix Receiver version 4.6 and is currently being investigated by Citrix.  In the meantime, we recommend exporting to the local computer to print in landscape format.  Please review the following Knowledgebase Article for steps to export files to the local computer:

How to export or save files from Blackbaud Hosting Services to your computer or network location:
http://kb.blackbaud.com/articles/Article/61532