Hi, just thought I'd share this info:

New plantronics discovery 975 would pair perfectly with phone (as confirmed by message on phone and flashing red/white light turning to just solid white on the headset), but incoming calls wouldn't ring into the headset and outgoing calls wouldn't be transferred.

As it turns out, with the centro you have to not only set up the bluetooth pairing through the bluetooth menu (under system preferences, or under its own icon from the menu), and once that has been successfully accomplished, you have to go to a separate menu, the hands-free menu, under the system preferences menu. 

Once you've clicked on "Hands-Free" in the Communication group of system preferences, you have to check the box next to "Always route call to Hands-Free" in order for any calls to be made or answered with the headset.

I chose not to enable Auto-answer, because I don't want to answer every one of my phone calls when I'm wearing my headset, but you can also choose this feature from this same Hands-Free preferences screen.  

I didn't think the palm site or any other sites explicitly stated this information in a clear, easy to use fashion, so I thought I'd provide it here in case I wasn't the only one that found Palm's headset setup a little more complicated than necessary.

=D