Frequently when viewing either the mission briefing or the in-game introductory sweep there is no sound playing, and the game apparently hangs, although I can skip the briefings as normal by pressing ESC. It's just like a video playback that's put on pause.
Any solutions for this?
I'm playing on XP.

Tried the usual compatibility modes and messing with the sound acceleration hardware slider?

I have this problem as well. It's very random.

Not a fix unfortunately but may shed a bit of light on getting it fixed.
I have / had this problem myself but when i got to mission 5 it starts working properly. I’m up to 8 now and it’s still functioning fine so I'm guessing it may be a blip with the first four levels. Could be a corrupt file out of the installer when it was repackaged maybe?

Got the same problem om Vista x64.

Ditto. Also on Vista x64. But pressing esc for me moves forward.

Yes pressing ESC moves it foward (skips the scene) and I can start playing the game, however I'd like to watch the intros - especially for the early levels which are set in Norway ;)

I have the same problem. Oddly enough, the sound almost always stops at different times. The narrator cuts out at random, and for the in-mission briefings, that usually short-circuits the camera motion as well. But not always: One time the camera began zig-zagging about, giving me a very silent view of the battlefield.
I've made it through the full first-mission briefing once, but that's it so far. All my other attempts have halted midway. One thing I have noticed: selecting "restart mission" almost never resets the briefing, if it was cut off. It usually requires that the game be restarted entirely.
A look at the game's briefing files shows that they're all stored in segments as tiny .wav files. 6 or more for each mission, it looks like. I'd guess something is wrong with the game's ability to schedule the start of one .wav after another has finished, but I'm not a computer whiz, so I have no idea why it would do that.

I had this problem, turned on windows 95 compatability mode and it *seems* to have gone away. It could easily be fluke though since I've only made it through about 3 missions since doing that.

I have the exact same problem, running Windows 7 RC 32-bit. On occasion I get more narration, but it always cuts out eventually. Visual briefing always hangs till I press ESC.

Yeah, this works. Thank you for hint. Setting compatibility mode to Win98/ME works fine too. Tried it on Windows 7 Professional (x64).

There is no music during the gameplay though. That's a bit of a bummer. :(

Is there meant to be music during the mission? My memory of this game is pretty vague, but I don't remember any in-game music.

I have the same problem in XP. You could try opening windows media player and leaving it idle in the background, this seems to have worked for me as the audio and music has been ok since.

I also encountered this problem in Commandos Behind Enemy Lines several times. I'm playing on a modern computer with Windows 7 Release Candidate 64 bit version. After changing the "Compatibility mode" to run this program in compatibility mode for Windows 95 , and also changing so that I run this program as an administrator I haven't encountered the problem at all. I have also gone back to see those scenes that I had a problem with and they worked flawlessly with those new settings.
I guess that compatibility mode for choosing either Windows 95 or Windows 98 doesn't matter but it's only a guess since I haven't actually tested it.