Calculating... until full

Ok, so I have just fully charged my MacBook ready to leave it on over night powered by the AC. However it has finished charging (CoconutBattery states it is, and a widget) but a when I click on the battery icon it says "Calculating... until full".

Is this normal behaviour? Also, the AC lead light is orange, is this right again?

Thanks,
virtual

Aha, 20 mins later it has finally stated fully charged.

Is this still a normal process ?