This is not a bug.
How can it show both the CD Audio Data and the Windows Files/directories in the same list?
There really are no such thing as "CDA" files.
Think about it. CD's came out in the 80's, way before Windows. Back then, when they made CD's, they weren't all sitting around and saying "Hey, let's call these CDA files." No, they are called CD Audio Data. They're not PC files in the traditional sense. They are something totally different than normal windows data files (EXE, TXT, MP3, etc).
Since they are not files, how then can Windows show them in the list of files? Yes, Microsoft tries to show them as these made-up "CDA" files, but if you look at a "CDA" file, you will notice that it is only 44 BYTES - It's what Windows uses to show you that there are songs on the CD. They are not really files!!!!! In fact, here is what one looks like:
RIFF$ CDDAfmt
YÛ` Üp <"
As you can see, it's not MUSIC! You can't put MUSIC in 44 BYTES!!! I don't care what kind of compression you are using.
This is not a bug.