This is caused by AUTO INSERTION NOTIFICATION being set to "ON" and having audio CD's associated with media player. This occurred automatically when you installed or upgraded media player.
It used to be real easy to turn off in the CD properties in device manager, but since Windows 2000, the setting is in another more obscure place.
Go to My Computer, TOOLS, FOLDER OPTIONS, FYLE TYPES.
Select AudioCD from the filetype list, highlite it, choose advanced.
From there you can choose what action you would like performed when a CD is inserted. You can also set it to start your other burner program.
step by step instructions