Logic Pro 8 sound card error


I'm not able to listen back the audio files while using the US 122L interface.
I do hear the input signal though. Tried to reset it and I've been resetting it in the preference mode of Logic by switching it from built in input to the interface.
Basically I've tried everything I know about this problem. I used to have it sometimes with my Mbox mini but I could always reset it.
it now seems it has crashed, although I don't have a clue how it should crash??
Anybody with any experience out there?