Are you installing version 1.4 or 1.5? This was a problem in version 1.4, but was fixed in version 1.5.

In case you are using the earlier version, we fixed it by modifying the sound.ini in the <FSX root>\Captain_Sim\767 folder like this.

Original:
[Common]
Refresh.Time=10
Sound.Directory=Captain_Sim\767\sound
SoundOffWhenSimIsSlew=1
SoundOffWhenSimIsPaused=1
SoundOffWhenSimDialogIsOpen=1
SoundOffWhenSimSoundIsOff=1

Modified:
[Common]
Refresh.Time=10
Sound.Directory=Captain_Sim\767\sound
SoundOffWhenSimIsSlew=0
SoundOffWhenSimIsPaused=1
SoundOffWhenSimDialogIsOpen=1
SoundOffWhenSimSoundIsOff=1

If you are still having problems, you can change all the 1's to 0's just in case. Remember that this is for v1.4 of the CS 767 Captain and not for v1.5.

Mark