Hey Munxcub! I used to have the same problem, but it would only happen if Toast itself wasn't open. If Toast was open and I put a disk in it was fine. Eventually there was an upgrade for Toast, and after that it started giving me the option to open Toast in the little dialog that popped up (the options are "open Toast", "eject", and "initialize"). Must've been the upgrade that fixed it, though it was from 5.01 to 5.02 and you are in a much later version. I'm sorry that probably doesn't help much, but I thought I'd let you know you aren't the only one who got that annoying dialog!!! If all else fails, might be worth uninstalling and reinstalling Toast - if your diskburner extension was still on when you installed Toast then maybe it caused a problem with the install??? Good luck man!
Steve.