Good questions - I should have included more info in the original post. It was in primary for 4 weeks, so I don't think settling should have been the issue. I use bags for my pellet hops which keeps most of that junk out of the primary. Break material is, perhaps, a possibility, but I've never seen so much in reading online or in my admittedly short tenure as a brewer. I tasted it a couple of weeks ago, so my memory isn't fresh, but it certainly didn't taste infected.
MW66 - Unfortunately I don't have a fermentation cabinet. I used a swamp cooler for primary and kept it around 63 F.
Ah another detail that I just remembered: The entire fermentation was rather slow, the pudding-like layer on the bottom began early in the fermentation, and bubbles were rising occasionally from that layer.
Also, I meant to type that I siphoned 3-3.5 gallons to secondary rather than 2.5-3...just for the record.
Thanks for the input, gents.