Audacious

You don't really "mount" an audio CD since there is no filesystem on it. Playing an audio CD just involves reading raw data from it. That said, there should not be any special tricks necessary. Have you already ruled out the possibility of a failing CD drive? In my experience, they often start failing to read certain disks a while before they get to the point of not reading any disk at all.

Hey man, sorry I didn't see your response! [I thought I was subscribed to this?]
The drive has just started failing to burn blank discs now too, no idea what's going on

Audio discs will 'load' most of the time but some just won't
Blank discs mount automagically without issue.

As jlindgren previously mentioned, it is probably a failing drive. I would just replace the drive with a $20 one from a vendor of your choice.

Our bug tracker and forums don't do email notifications for some reason. I'm not sure if it was never set up, or something broke it along the way.

The bug tracker sends e-mails, at least for me. :)

Yeah no alerts for subscribed threads is annoying.
I'll just get another drive, this thing is making noises too...