After upgrading to 2b7, I left my empeg playing in my room, lined in to my stereo. After a while, I noticed a sine wave, as mentioned herre. Sounded like it coincided with something inside the player. Don't think it was the hard drive, which was my first guess.

Anyhow, left it off for several hours and it stopped. It still does it when very hot, so I'm thinking there may be a fan in there or something.

Could this be what we are experiencing?

Those cars with better ventilation in the dash would get it less and stuff.

I did not experience it with 1.3, but then I didn't really put it through it paces as much :)

I'm probably crapping on about nothing, but I thought it might be a valid point....