Hayo,
BTW - I am surprised you are embedding XMP and IPTC into your NEF files now that you have moved to Adobe workflow. I would recommend that you always force an XMP sidecar and NOT modify your RAW files as this is the safest way to handle RAW files and is what Adobe expects. And since Adobe won't update any embedded XMP that may already exist, you could be reading stale data. Best solution is to not modify RAW files, always force XMP, and read XMP sidecar first (if present), then embedded XMP, then IPTC as last resort.
Regards,
--dennis