All good information but it doesn't answer the question. The Adaptor supplied with the latest Ipad is more than adequate to supply the Classic and so I would expect the charging symbols to appear. When using the standard 5w charger the Ipod displays the charging state correctly but when using the 10w charger it gives the impression that it isn't charging even though it is. One snippet I didn't say is that the charge symbol only showed a 50% charge when in actual fact it was fully charged.
Anyway thanks for your interest if I find an answer I let the community know.