I'm struggling (failing!) to get my Stream radio to playback all the MP3 tracks on a CD containing multiple folders.

As a simple example, say the CD contains:

/track1.mp3

/track2.mp3

/folderA/track3.mp3

/folderA/track4.mp3

/folderB/track5.mp3

/folderB/track6.mp3

If I set mix to 'folder' and repeat to 'folder' it only plays the tracks in the current folder where I'd expected it to play all 6 tracks in random order. Am I misreading the manual?

The settings you have will result in random play in the current folder only.

just read the manual, and mix folder is what you want, you cant have repeat with mix across multiple folders.

for repeat folder the manual says:

if mp3 disc is inserted the tracks in the folder active when the function is activated will be played repeatedly.

Ah. OK. So if I set mix to 'folder' and repeat to 'off' then it should play all the tracks in all the folders in random order?

Yes, I believe so. You need mix set to folder.