"Services" menu
Sometimes I am told my "Services" cannot be used, ie. "Initial caps to words". I can't find any solution but by changing the type by hand.
iMac
Not every application supports services. Not every service is available to every app.
So it would help us understand your issue better if you mentioned what application or applications this service doesn't work with.
Also check System Preferences > Keyboard > Keyboard Shortcuts tab > Services item to make sure "Initial Caps Of Words" has a checkbox next to It.