For some of my users, but not all, when they drag and drop an attachment (tested with both .pdf and .docx) into the explorer view window of a document library it appears to copy it over, but in fact the size of the file in the doc library is 0kb. So the doc icon and title appear, but the document isnt really there... These users can reset all their Internet Explorer (IE9) factory settings and it will temporarily correct the issue. But it will soon return.
Has anyone seen this before?