Xyz2grd - "no data" option not working as expected

I’m converting a lot of x,y,z points to a grid but am having probs getting xyz2grd to make missing triplets =0.

I used: -di0 but missing triplets end up as: NaN

Manual states:

-di nodata
Replace input columns that equal nodata with NaN. Also sets nodes with no input xyz triplet to this value.

Any ideas?
PS: GMT 5.4.3

Dang. Just found the problem (answer). Nothing like posting something to make you see things a different way!