Creating a CD Track marker doesn't always do so

I've been carving up a narration using CD track markers, prior to exporting to separate files.  Every so often, after selecting a segment and then hitting Ctl+M, it gives me a cue marker instead of a CD Track marker.  If I'm not watching carefully in the marker panel, it messes things up.  There's no End or Duration time. 

If I switch it from Cue to CD Track in the Type list, though, the end/duration show up.

It probablyhappens 1 out of 10 times.  Just an oddity to watch for.