Ok, I have now installed the windows beta client (= bug reporting tool), and filled out some forms already. Looks like they want to have very detailed information, though.
Scawen, would it be much work to write a small test app? I don't know if they will be willing to download the whole LFS archive just to test this.
However, the sound starts to come up at a sound lag of about 0.22, but its almost only noise, and very stuttering. When you increase the sound lag further, its gets louder, and the noise is very strong at 0.24, and you begin to hear an engine rev through it. At 0.3 it seems clean.
Im sorry that I can't record the sound, maybe that would help already...