Kirk,
Thanks for the reply.
I did a test, ingesting a card that included shots from the last two weekends, the prior weekend's shots having been already ingested before the switch into a dated subdirectory.
One difference, for the ingests from the old machine, I preserved the source directory, namely that structure found on the CF flash cards from my Nikon bodies. Today's, on the new machine, I did not check off the preserve directory structure tick box. Still it re-copied the last of three previous days' shooting that were on the card in addition to the new photos shot this last Saturday.
This is hopefully a set up error on my part. I note that the data on IPTC window was a clean start.