S'right. They click whenever the units cycle from, say, Dolby 2.0 to Dolby DD 5.1 to DTS HD-MA, to DTS-HD MA+PlIIz and so on. The only way to minimise it is go into the menus and set every codec to a 'default' output - eg set the lot to PLIIz (which I do). It can be annoying when watching TV where the formats are all over the place during commercials, for example. And on Blu-rays where the trailers do the same sort of thing.