Thanks Amos. I'll look what's in "Permissions" and see if there's something going on....

I've already changed the name to......"Can't Trash". There's now nothing in any of the folders to access as I've downloaded the MP3s to an iPod, and so taken them off the Mac. I could use these folders for general storage, but they're cluttering up the desktop, and may be a symptom of something else going awry.

I've had this Mac over six years - never any problems on it, so I suppose I've not much to complain about.