Random folders containing whole albums, visible only on sdxc card (invisible thru artist or album directories as previously posted), will not play at all. When attempting to play any song within said folders, the prompt "Invalid File" appears. Additional attempts to play any songs from said folders result in PD green screen or frozen, unresponsive screen, requiring hard reset which fails to remedy folder issues. Error checked sdxc card using Windows 7 disk properties tool: clean bill of health. Furthermore, music files in said folders play without issue via itunes and quicktime. Majority of ALAC files seem to play without issue. I could delete and recopy said folders to card, and this may solve the problem for these folders, but how many other such folders are lurking there I have no way of knowing without checking each and every folder individually. Even at a modest 30gb this is a massive, onerous task. I have spent tens of hours copying music folders, wrestling with id tag mysteries, and now troubleshooting weird PD behavior. Unit appears to be, at best, a beta product. I am really disappointed and burned out on this thing. Gonna miss the sound though.