The trick to getting Tone's CD to work is correctly setting the volume label on the disk when you burn it. I think the correct volume label is "vcross00" but don't quote me on that. I'll double check my CD for you when I get home if you want, or someone else can chime in.

As far as overfilling, I let it go until it clicks and leave it at that. I've never had any issues with that charcoal canister, FWIW.