Volume Down appears to work correctly for me in it's default configuration.

These are the only mappings I use though:

[ir_translate]

00000010=0020df14     ;Stalk Left Side Button ---> Remote Info

00000014=00000004     ;Stalk Previous Knob ---> Front Previous

00000015=00000002     ;Stalk Next Knob ---> Front Next

80FFFFFF=0020DF0d     ;Stalk Bottom Button ---> Remote Shuffle

00000035.T=0020df15   ;Stalk Shift Vol Up ---> Remote Visual   (Tuner Only)