I use Toast Titanium 7 on an eMac G4 (PPC), OS X 10.4.11. I recently found that audio CDs that I have burnt (using Toast Titanium and my Mac's built-in optical drive) took a very long time to mount when re-inserted into the drive at a later date. The drive made a rhythmic noise for up to 2 minutes before settling down and letting the disc icon appear on the desktop.

After much investigating, I discovered that on a previous occasion, when I was making a multi-session data CD, I had left the advanced recorder settings at 'write session' instead of 'write disc'. When I re-set them to 'write disc', the problem with newly-burnt audio CDs disappeared. (There is presumably nothing that I can do with the old ones!) But what puzzles me is that it is in any case impossible to make multi-session audio CDs — so how and why did leaving the recorder set to 'write session' affect the way audio CDs were burnt? I should be most grateful for any ideas or information about this.

It is possible to add data sessions where the audio CD is the first session. As for the CDs that are still open you could add an empty data folder and choose write disc to close the disc. Don't do this without first copying the tracks to your hard drive because I'd hate it if you followed my advice and the disc became unreadable.

That's the first intelligible answer to my puzzle that I have received from anywhere, Tsantee. (My daughter lives in Oregon, too; too far from me in the UK, I'm afraid, but the Oregon air is clearly good for the brain!) Not only intelligible, but extremely useful, too. I shall try what you have suggested straight away.Thank you.

Well, I tried it. I was able to record an empty folder as a data recording, using the 'write disc' setting. The original music tracks were untouched: the CD played perfectly well in my CD player (as it did before). (I did, of course, as recommended by you, Tsantee, ensure that I had the music tracks backed up on my hard drive just in case…)

There was only one trouble: when inserted back into the optical drive of my computer, the CD still took just as long to mount as it did before!

On reflection, that makes sense to me, because multi-session data CDs always take a long time to mount. But at least I now understand why the 'write session' command has an effect on an audio CD. And I know what not to do when I next record an audio CD.