When the 2408 is communicating with the PCI-324 card you should see the Clock, Source and Bounce leds lit up, or just the Meter led lit solid, not blinking.

With a 1224 you should see one sample rate led glowing steadily as oppossed to both 44.1k and 48k leds blinking.

Set the Clock Source to Internal and hit Refresh.
Try restarting the computer if Refresh doesn't regain communication.
Make sure the AudioWire is in tight on each end.
If you still can not regain communication, try one of the other AudioWire connections on the PCI-324 card and then hitting refresh with the Clock Source set to Internal.
Try reseating the PCI-324 card in the computer or even try another PCI slot if you are still having trouble.
If you still have trouble you should contact our technical support department for further assistance.