I have the DG45FC board and I am using the Optical out to connect to my home theater amp. I originally set-up the IDT Audio to "Enable Dolby Digital Live" to allow the Dolby signal to be sent to my amp and processed. With this option selected, my computer continually crashes when playing Flash content in any web browser. As soon as I disable the Dolby Digital Live then everything works fine except I don't have a Dolby signal for the amp to process, so no surround sound. I have the latest driver (6.10.622.4.7) and I'm using Windows 7 32 bit.