Since you're one of the few (if not the only one) with this specific problem, I'd recommend you to check out your sound configuration. Some games cause problems with specific settings and hardware, e.g. I can still remember Bioshock had such issues while Stereo Mix was disabled (enabling it solves the problem). You could search for most common sound problems with other games and hardware configurations (something like this) and try to apply custom settings in order to resolve the issue with 2238.
He is not the only one with these problems, there is an entire thread where we tried to pin down why it doesn't work for us anymore (unfortunately I can't find it right now). It stopped working for a lot of people since a certain SDK revision, so I wouldn't only pinpoint it to a PC configuration (I compared my PC configuration with others with the same problems and they are vastly different).
And yes, me (and I assume Jack and the others too) fiddled around for weeks already with different sound configurations, it does not work. The engine plays .ogg files for us just fine, all the .acm files are kept silent - that's why I assume it is NOT an issue with our respective computers.
