It 's solved but I did not find it myself (credits to WARD - my personal guru)
2 problems I encountered:
1: the included API 1.0 example sketch is not correct
(UNACCEPTABLE that this is not correct in an example sketch, people get confused and loose Arduino appetite)
2: make sure that the key you created in the Pachube website has
Permitted Methods all
I would NEVER have found this myself, the Pachube website urgently needs a simple, correct, straightforward geting started file on the home page and all outdated data should be updated or deleted.