If you are using 10.7.3 and smart cards, please update to 10.7.4.
We've just received the 10.7.3 released version of OS X.
We did some testing with smart cards and can confirm that the login dialog now properly prompts for the smart card PIN when the card is inserted.
First a little background information. When 10.7 was released, Apple had removed the drivers to support specific smart cards types, but left in the underlying smart card infrastructure. Centrify has built replacement smart card drivers in our DirectControl product. We provide native support for CAC, CACNG and PIV smart cards.
This was available when 10.7 shipped, but a small issue existed with the login screen. It wouldn't properly recognize when a card was inserted into a reader, and the user wasn't prompted to enter their pin.
Fast forward to 10.7.3 and now the small issue with the login screen has been partially resolved.
However, there's a trick to it.
If your login window is configured to display the Username and Password prompt, then it won't work. When the card is inserted the login screen will go blank.
(No pin prompt is displayed. In fact, nothing is displayed)
You need to set the login window to display the "List of Users".
Now when you return to the login window and insert your card, you will see something like this :
This display problem is a bug and it's been reported to Apple.
However, if the card is inserted and the screen doesn't change, or blink, or switch to the pin prompt, or go blank it means you have other problems related to your smart card trust chain. We've done a lot of work figuring out how to diagnose those types of problems.