I was able to solve my audio drop problem by unstalling the latest version of VideoLan and reinstalling the prior version. Everything works fine using the prior version. There must be some audio bug in the current version.
When playing a ripped Blu-ray movie file in .mkv format, the audio drops out for a second or less every 90 or so seconds. I'm using a new MacMini and running the latest version of Lion. The video is perfect - the only problem is the "clipped" audio at regular intervals. I'm just a beginner...