Ok, that's a shame. But all hope is not lost, I'll throw you some ideas that have helped one or two with RBR's (totally unrelated) sound problems in the past. However, when I considered that last one a long shot, that was nothing; the following will be just lottery. Be lucky.
1. Is there eq_mix.dll in your Plugins folder? Try removing it to see if it makes any difference. It shouldn't but try anyway.
2. If you have changed Audio.ini's NumberChannels entry from 0 (zero) to something else, you may want to go back to 0. Or alternatively, you could experiment with it like John did there.
3. If you're using 5.1 surround sound setup or something, you probably would like to go back to basics again and test a more basic 2 channel setup.
4. If you do own a soundcard, it may have a sample rate setting. If it's currently something over 48000hz, you'd probably want to drop down to mentioned 48000hz or even 44100hz.
If none of these sort it out for you, I expect nothing will, ever. But I guess that replay thing isn't that much of an issue, anyway.