Hidden layer? Hidden object on a master page?
I've used "select all" and "over-ride master page" with no luck
That's an old bug that we came across in every version of Indesign for many years. I haven't seen it in CC versions though - are you using an older version of Indesign?
There was no consistent set of circumstances that triggered it, it just happened every now and then.
It seemed to be that the glitch was something that was tied to just the document rather than the content itself - so the fix was to copy the content to a new document.
Peter, you were right! Selecting all isn't going to parse out a hidden layer, which didn't dawn on me earlier. Checked my layers pallet when I got home and sure enough, (somehow/mysteriously!!) there's a hidden copy of the logo. Feeling kinda dumb right now, but I'm really glad the problem's solved. Thanks!