Odd- tuned up a couple of guitars and a bass to the built in tuner. Loaded B-3 software instrument- all seems in tune. Loaded 3-4 different suitcase pianos ( not at the same time) and they are a 1/4 tone flat- sometimes it slips up and down in pitch a tiny bit. Played with the sliders, no change. Btw- first Gen Axiom 61 midi keyboard. QC iMac 27". Weird?