Check the post from StevenJGore
here.
StevenJGore wrote:
For some reason, OS3.9 will only allow the CD32's built-in CD drive to be used on the second boot. In other words, when you first switch on the CD32 and boot into OS3.9, the CD drive won't be available. You have to reset the CD32 and boot into OS3.9 for a second time, and then the CD drive will be available for use. It will also be available after every subsequent reset, until the power goes off. I've no idea why this happens, but it doesn't happen with WB3.1, and it doesn't happen with OS3.9 running under CD32 emulation in WinUAE.