umm... uhh... You are selecting emphatic from the Hijack menu first, right? Also, how do you know the volume buttons are working to move the menu selection left/right if you can't open the menu? I'm confused.

Yes, selecting emphatic from the Hijack. Only after that I can use the REW / FF buttons as Vol- / Vol+.. Before selecting emphatic from the Hijack menu the REW / FF buttons truly are REW / FF.
So the mapping works for those two buttons. Got it?
Try mapping your Kenwood from your apartment, then get some sleep, drink some coffee, do some stuph and I'll be getting back to you. d=) (it's 1.30am here, going to bed, now.)