I've only managed to have the sort-of MLU once, on an MX which I think had probably been sitting in someone's wardrobe for decades (judging by the batteries in the flash it came with - they hadn't leaked but had a Duracell logo I hadn't seen for years). Hasn't done it since, and neither have any of my other Spotmatic-derived cameras (Spotty, KX, and another two MXs).