VVX D60 no lines mapped

I have taken my VVX 600 and attached a D60 to it. Setup is quick and easy, just added this config:

feature.dect.enabled="1"
reg.1.terminationType="VVX-DECT"
VVXD60.Handset.1.outGoingLineIndex="1"
VVXD60.Handset.1.line.1="1"

Though the phone shows everything set up correctly the handset is not working. All I see on the handset is a zero. I can provision a second line and that seems to work fine, but I want the same extension on both the 600 and the D60.