cannot enable 'Tagging opencalais suggestions' - Calais_api (missing)

Hi,

I have the following modules enabled ...
OpenCalais - 7x alpha2
OpenCalais API - 7x alpha2
rdfx - 7x alpha4
added the libraries for ARC
added the api key after registering with calais

Calais is working fine, but still cant get the Tagging opencalais suggestions enabled - its grayed out.

says calais_api module is missing.

'Requires: Taxonomy (enabled), Options (enabled), Field (enabled), Field SQL storage (enabled), Tagging (enabled),
Calais_api (missing)

Not sure if I am missing anything or if the tagging module is looking for calais_api when it should be maybe opencalais_api?

thanks in advance.