using "ExifTool by Phil Harvey" I was able to track down the problem. The current version of Windows Photo Gallery is no longer tagging to the IPTC space. It tags to Exif:XPKeywords (0x9c9e) , XMP-dc:Subject, XMP-microsoft:LastKeywordXMP, XMP-microsoft:LastKeywordIPTC , But not to IPTC:Keywords.
I don't know if this merits a bug report, a code fix, or any further attention... once I figure out how to have the tags copy over from one part of metadata to another, I will post my solution.