This might seem like an odd question, but audio anomalies are a bit harder to pin down compared to picture defects. I've noticed a few audio problems recently on different discs and am unsure of how to proceed. For example, during the final quarter of 'Driven' it *seemed* like the center channel dropped off to almost nothing. Center channel was already set to +10db, dialog was still unintelligible. I had to boost the overall volume to almost 100% and then reduce it when the soundtrack came 'back' later. This was the most recent example, but there have been a few other situations (The Fog) where it *seemed* like there was a mysterious loss of volume during the later part of movie. I don't think it's my hardware, because its only happened on a few movies, but I am using a 10 year old Pro Logic system. There may be some quirks with the 5.1 fold-down process, but it's hard to imagine how this could affect the center channel. Is is possible these disc are defective?