have show hidden files turned on?
I use office 2007 and pdf and i haven't ever seen the 0 byte files that you are talking about.
My system (WinXPSP2) generates 0 byte files for some reason. The files are associated with other MS Office or PDF files and prohibit the associated file and the 0 byte file from being moved, copied, or deleted. Frequently, the MS Office or PDF file that is associated with these 0 byte files is corrupted and unreadable; other times they are not. There is apparently no virus per NIS 2008. Some of these files are opened and used frequently and others have not been used in months. I am looking for suggestions concerning the possible cause(s) and solutions. I have been able to delete these 0 byte files with Unlocker. These files interfere with backups and file maintenance.