Also, keep in mind that there is additional functionality in the new Rio remotes that the original Kenwood remotes lack -- like press-and-hold.
Actually, some buttons on the kenwood can do press-and-hold (volume,ff,rew)., but most buttons only send IR-codes once. The IR-driver sends a button-down code when it receives the first code. when it doesn't receive that same code in the next 200ms, a button-up code is generated. This way the player app can set it's own repeat intervals and timeouts for press-and-hold. At least that's how I think the new code works. Thanks for the extensive documentation of the kernel source...

Frank van Gestel