When a track if greyed out, it means the song is either not there anymore in the same place, or has been deleted. It could mean your MM was reading the songs on your device, and when you unplugged the device, the songs weren't "there" anymore, and thus were greyed out.

Don't add tracks from your portable device into MM (by using file -> Add/rescan tracks library) or turn off filemonitor for your portable device.

Hi,

I was using adding tracks to a small USB MP3 player which worked a treat.

But now when then USB player is disconnectred the tracks that I added to it now appear in the library (but are grayed out) and look like duplicate entries.

Can this be avoided?

Thanks,
Steve