How can I get Logic Express 9 to recognize new instrument pthe new instrument plug-ins that come with a jam pack?

Hi,

I installed the World Music jam pack and it contains several instrument plug-ins (such as "Voice" and "Woodwind") that didn't come with Logic Express 9. I've confirmed that yes -- the installation put these plug-ins in the Plug-in Settings folders for both Garageband and Logic, yet when I create an instrument track in Logic and try to load one of the World Music instruments from the Library (let's say one of the African Choirs) I get an error message saying that the "Voice" plug-in isn't available. Nor does it appear in the list of plug-ins I get when I click on the instrument slot in the channel strip. Any instrument installed from the World Music disc associated with a plug-in that came with my original Logic Express 9 program (such as "Drum Kits") loads and plays normally. Any idea how I can get Logic to recognize those new plug-ins that came with the jam pack?

Any suggestions or feedback are gratefully accepted. In advance -- I appreciate your help.

Rick