I've used matte spray lacquer on my paper CD labels for quite some time and have heard of no "gum up" problems.
Just a light dusting dries in a few minutes to a coating that can not be seen or felt. There would not be anything in a CD player that would soften or desolve the lacquer on the CD. I wouldn't be surprised if the paint that is used by the manufacturer on the direct print CD blanks is of a lacquer base.
The problems that I have had with paper labels (sprayed and not sprayed) is that some of the CD players in Chrysler product automobiles have such a small slot that the CD's jam and will not come out due to the added thickness of the paper label.
Just my thoughts,
Walt