[gembud] dcgrib2 failing with CMC's NAEFS

When I try to decode ensemble gribs from CMC's NAEFS using dcgrib2, with a 
grib2 file containing 21 members for one timestep, I only get two in the gempak 
file,  The degrib program shows that there are 21 grids in the grib file.
I have tried it using GEMPAK 7 and GEMPAK 6.4.4.
One of the grib files I tried was downloaded from here:
http://dd.weather.gc.ca/ensemble/naefs/grib2/raw/00/006/CMC_naefs-geps-raw_VGRD_TGL_10m_latlon1p0x1p0_2015100800_P006_allmbrs.grib2