A ripten writer noticed this on his Dell laptop. Linkage between Dell (and other OEMs) and the RIAA were posited an obvious theory. Now, while I wouldn't put it past the RIAA to do this, I have what's probably a more likely theory: driver bug.
Notably, these incidents seem to have occurred on laptops using a SigmaTel sound card. SigmaTel pretty much owns the OEM market for laptops, as evidenced by how many laptops were affected by the "old Sigmatel" driver which prevented them from upgrading to Windows Vista SP1.
So these drivers aren't exactly bug-free. That and a post in the ripten comments section, apparently by a Dell Digital Life Liason (and I've dealt with them in the past) stating:
My name is Chris and I’m a Community Ambassador for Dell computers.The release date of that driver is 12/20/2007, so it's not even a new fix. So, it sounds like a simple driver bug, but not all are satisfied. Bug sounds more likely than a conspiracy, but what do you readers think? As I said, I wouldn't put it past the RIAA, but still ...
You didn’t state in your post, but the links you forwarded to indicated you were dealing with a laptop with Windows XP.
If this is the case, our Sigmatel R171789.exe XP drivers unlock the “Stereo Mix” feature. Refer to the following link:
Please let me know if you have any additional questions regarding this feature.
Dell Digital Life Liaison