Well, I maybe found the problem. 1: I had an unhappy fan in the system -- and it's the one that cools the card slot area... 2: I think the controller card was getting warm anyway -- so I also changed the venting and put a temp sensor (CrystalFontz SCAB don'tcha know.. with dallas 1820 1-wire thermometers)... so I'm gonna keep an eye on it now. 3: I set up Munin to keep track of mismatch_cnt on all volumes. Didn't even know it existed.. :( wish I had history. I will now going forward. I'll let ya'all know. As usually... awesome help -- thanks! -Ben -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html