I explained this phenomenon to Temple University prof John Allen Paulos, an expert in applying mathematical theory to everyday life. His conclusion: it's entirely possible that nothing at all is amiss with the shuffle function. It's quite common for random processes (like coin tosses) to get unlikely results here and there, like runs of six heads in a row. Over a very long time, it evens out, but it's hard for us to envision that. "We often interpret and impose patterns on random processes," he says, adding that this might be expected in the case of music, which evokes strong emotions. Paul Kocher, president of Cryptography Research, puts it another way: "Our brains aren't wired to understand randomness."
Life may indeed be random, and the iPod probably is, too. But we humans will always provide our own narratives and patterns to bring chaos under control. The fault, if there is any, lies not in shuffle but in ourselves.