Does anyone get occasional popping and clicking when listening to MP3s from a flash drive? I've tried different flash drives, and have had the same issues. It's only occasionally, and I can't seem to figure out what makes it start or stop. I can skip to the next track, or next folder, same issue. And then sometimes (usually) it's fine. Doesn't seem to matter if it's constant or VBR, or if they were purchased from Amazon or ripped from my own CDs.