Hello Wilfried,
Well, it seems we need to update the api.
The URL to use now it:
api.bitfinex.com/v1/<whatever>
As such, the parameter
"request" that you send must be
'request':'/v1/<whatever>'
instead of
'request':'/api/v1/<whatever>'
Let me know if it helps, I'll update the wiki soon.
Raphael
Bitfinex team