Under gutsy there was a listing for my HP DJ5650 printer in the list of HP
printers when configuring printing. Under hardy, the 5650 isn't listed; the
nearest matches being 5550 and 560C.

Is this an error omission or of comission. Which should I use or how do I get
5650 support?

Have you checked to see if you have _all_ the gutenprint stuff installed? It could be that
the one package that contains the drivers for your 5650 is not installed.