"fresh" as in repair-install, or as in clean, completely-from-scratch install (from the installation media, not using the system builder's recovery system, if applicable)?
If it occurs on an installation that has no real configuration changes, and no manufacturer bloatware utilities installed, that would be quite strange.
Theoretically I suppose it could be a driver issue, but given that this issue is extremely rare, that would have to be something fairly exotic, perhaps a specific combination that causes it.
What soundcard are you using? Do you have a USB headset?