When I installed FS2002 a couple of weeks ago, I was deeply disappointed: The teacher's voice was completely garbled.
I checked the .wav files, but they were o.k.
Any external .wavs that I played during FS2002 also sounced fine.
System: Abit KT7 raid, 384MB ram, Geforce2 MX, Soundblaster Live! player, Duron 800MHZ, win ME.
When I started to look for a solution, I found that Combat Flightsim 2, which I hadn't played in a while, also had started stuttering, gun's went silent, etc.
I then found that the directX diagnostic tool played incorrect sounds in the direct play test. Full hardware acceleration on the soundcard didn't play software buffers, and no acceleration played software buffers only.
It took me about a week out of my holiday, and a couple of new windows installs, including going back to win98 to figure out what was wrong.
In the first place, it turns out that driver versions have very little to do with it. Going back to very old bios- and sound-, video- and via chipset driver- versions didn't help at all for this. They just helped stability.
Only when I reformatted the hd and installed win98, I had a working system. Updating the drivers to the latest available, did NOT make a difference, all worked fine. (maybe this helps people with related problems).
The problem turned out to be in windows itself (should have known), it's apparent in both win98 and winME.
Because I have a fair amount of memory, and wanted my system quicker in booting and more stable when recording video, I had turned off the virtual memory. (On booting, windows writes back about 60MB of stuff to the harddisk, even though there is plenty of memory available).
(When doing disk intensive and timing critical stuff, like video recording, virtual memory kicking in can easily cause losted frames etc, so you're better of without. In theory, this could make your computer less stable though, if you let it run out of memory)
This seems to work nicely, but it has the strange side effect of making the sound stutter in FS2002 and CFS2. Maybe in other programs too, I don't know.
Most likely some sort of buffer management problem.
I solved it by giving the virtual memory setting a 0-1MB space.
This is effectively zero, but the stutter is gone.
Also, the directx diagnostic test works fine now.
Hope this helps somebody :-)