I have an EyeTV DDT running on an oldish Intel 21" iMac with up to date Lion. It's running the latest version of EyeTV 3 software and exporting all recordings to the iTunes library. This set-up has been working well to stream to an AppleTV via Ethernet for years.
I've recently started having an issue where the audio drops out leaving the video running in silence at a random point through the recording. This silence continues to the end of the recording.
I have found a workaround; take the raw Eyetv file and encode it using Handbrake, but defeats the object of EyeTV's nice automation.
I have't noticed that I've changed anything in settings since it worked fine. The only thing that I regularly do is update eyeTV software as it is released.