It has nothing to do with amplifiers, the pop is a side effect of the player shutting down improperly, which traditionally is caused by the power control PIC crashing (remedied by the diode cable for early empegs, never an issue with Rio's).

The PIC is programmed during manufacturing and the code is never changed.

It's very odd that 2.x would fail to shut down properly while 1.x works OK. It's also very odd that only two people seem to have reported this, unless I missed something. We've never seen it happen here.

We've fixed many dozens of bugs and reworked some of the code since Beta3 (we're about to release Beta7 to the alpha team) so I suggest you stick with 1.x for now. Try the next public beta and if it still happens we'll look into it.

Rob