Hi Chony, I totally concur. That said, I'm interested to find out from you if the style part volume bugs only occur with 'custom samples', or if they are happening with preset styles & internal voices too, because in my limited testing, I couldn't get it to happen when utilizng preset styles that call up internal voices, though I did notice that the volume levels of 'inactive' style parts did change erratically. Luckily because these weren't actively used style parts, it didn't affect the sound of the style. Chony have you tried or noticed this when editing the part vols of Preset Styles? Thanks - Scott