I've been experiencing this issue for a while now, but was under the impression that it was related to my old computer, however, after purchasing new MacBook Pro, Amadeus Pro still displays the same behavior.
The issue is intermittent, but consistently reproducible.
When burning CD's, after recording is done, Amadeus Pro ejects the CD, however, Burning Status window never goes away. Inserting another blank CD into the drive, at this point immediately causes Amadeus to become a zombie process and killing it is impossible, unless you reboot the computer.
Force Quit does not help, killing the process via Terminal does not help either, and `ps' shows the process is "(AmadeusPro)" which is a typical Unix sign of a Zombie process. Those never go away, and it's impossible to kill them and in alot of cases these are related to hardware not being released by a certain driver or process
Now, i found a strange workaround that helps, but would be nice if these stopped happening.
As soon as it ejects the CD and you see that the Burning Dialog still there, exit Amadeus, hit the Eject button on the keyboard so you hear mechanism try to eject the CD. After that re-open Amadeus and it's back to normal.
How often does it happen? Often enough to piss me off

I am burning my new dj mix and so far burned about 20-25 CD's today.
During that time I had to quit from Amadeus 6 times, so to me its pretty serious.
I am burning a 153Mb Amadeus file, with 16 markers, at 8x speed on a brand new MacBook Pro, but I dont think it is hardware related. My old MBP (1st gen Intel) experiences exact same issue with same consistency.
thanks
igor