Created attachment 27157 [details] git format-patch @ svn-id 1135656 POI is returning the created property rather than the lastPrinted property in getLastPrintedPropertyString. When saving documents which have a null created property and a valid lastPrinted property, this resulting docProps/core.xml file has an empty lastPrinted node: <lastPrinted></lastPrinted> which PowerPoint 2011 for OSX detects as a corrupt file (I have not tested other formats or other Office versions).
Applied in r1135997 Thanks, Yegor