Load(): Interpolation issue

As @nmishra reported, there's an issue when loading ncep/system2_m1 data.

library(s2dverification)
library(ncdf)



# mask for MODEL
# --------------
fnc <- open.ncdf("/esnas/exp/ecearth/land_sea_mask_512x256.nc")
lataux <- get.var.ncdf(fnc,"lat")
lot <- get.var.ncdf(fnc,"lon")
maskaux <- get.var.ncdf(fnc,"LSM")
close.ncdf(fnc)

nlat=length(lataux)
if (lataux[1]>0){
  lataux=rev(lataux)
  maskmod=maskaux[,seq(nlat,1)]
}

maskmod[which(maskmod > 0.5)] <- 1
maskmod[which(maskmod < 0.5)] <- 0

#maskmod=t(maskmod)
listmaskmod=list(maskmod, maskmod, maskmod, maskmod)




# mask for OBSERVATION
# --------------------

#fnc <- open.ncdf("/esnas/exp/ecearth/land_sea_mask_512x256.nc")
#maskobs <- get.var.ncdf(fnc,"LSM")
#close.ncdf(fnc)
#maskobs[which(is.na(maskmod))] <- 1
#listmaskobs=list(maskobs)


#masklst=list("/esnas/exp/ecearth/land_sea_mask_512x256.nc")




# load NOVEMBER start date seasonal data - DJB
# --------------------------------------------

  # generate dataseq for NOVEMBER start date
  # ----------------------------------------
  Novstart <- as.Date("19921101", "%Y%m%d")
  #Novend <- as.Date("19921101", "%Y%m%d")
  Novend <- as.Date("20121101", "%Y%m%d")
  Novdateseq <- format(seq(Novstart, Novend, by = "year"), "%Y%m%d")


# NovStartData=Load("tas", #prlr
#                c( "glosea5_sea", "ECMWF_S4_sea", "NCEP_sea", "MF_sea"),
#                obs = "ERAint", #GPCP
#                sdates = Novdateseq, leadtimemin = 2, leadtimemax = 4,
#                lonmin = -20, lonmax = 70, latmin = 25, latmax = 75,
#                storefreq = "monthly", sampleperiod = 1, nmember = 51, output = "lonlat",
#                maskmod = listmaskmod, #maskobs = listmaskobs,
#                grid = "r512x256",
#                configfile = "/home/Earth/nmishra/s2dv_test/BSC_chloe.conf")
  glosea5 <- list(path = '/esnas/exp/glosea5/specs-seasonal_i1p1/$STORE_FREQ$_mean/allmemb/$VAR_NAME$/$VAR_NAME$_$START_DATE$.nc')
  NovStartData <- Load("tas", #'prlr'
                       exp = list(glosea5,
                                  list(name = 'ecmwf/system4_m1'),
                                  list(name = 'ncep/system2_m1'),
                                  list(name = 'meteofrance/system4_m1')),
                       obs = c('erainterim'), #'gpcp_v2.2'
                       sdates = Novdateseq,
                       leadtimemin = 2, leadtimemax = 4,
                       lonmin = -20, lonmax = 70,
                       latmin = 25, latmax = 75,
                       storefreq = "monthly", sampleperiod = 1,
                       nmember = 51, output = "lonlat",
                       maskmod = listmaskmod,
                       #maskobs = listmaskobs,
                       grid = "r512x256")