[gradsusr] grads 2.0.a8 refuses to open netcdf file that 2.0.a7 had no problems with...

[Geert Jan van Oldenborgh]

I am upgrading the Climate Explorer (http://climexp.knmi.nl) to a new box, and got the latest version of grads for it.  Curiously, the first netcdf file that I tried did not open in the new version, although it worked fine with 2.0.a7.  The error message is an unhelpful "gadsdf: SDF file does not have any non-coordinate variables" and the file is http://hadobs.metoffice.com/crutem3/data/CRUTEM3.nc.  The headers are

[bima] [13:54] ~/NINO/CRUData% ncdump -h CRUTEM3.nc
netcdf CRUTEM3 {
dimensions:
	longitude = 72 ;
	latitude = 36 ;
	unspecified = 1 ;
	t = UNLIMITED ; // (1924 currently)
variables:
	float longitude(longitude) ;
		longitude:units = "degrees_east" ;
		longitude:point_spacing = "even" ;
		longitude:modulo = " " ;
	float latitude(latitude) ;
		latitude:units = "degrees_north" ;
		latitude:point_spacing = "even" ;
	float unspecified(unspecified) ;
		unspecified:units = "unspecified" ;
		unspecified:positive = "up" ;
	float t(t) ;
		t:units = "days since 1850-01-01 00:00:00" ;
		t:time_origin = "01-JAN-1850:00:00:00" ;
	float temp(t, unspecified, latitude, longitude) ;
		temp:source = "No field processing" ;
		temp:name = "temp" ;
		temp:title = "Temperature T" ;
		temp:date = "01/01/50" ;
		temp:time = "00:00" ;
		temp:long_name = "Temperature T" ;
		temp:units = "K" ;
		temp:missing_value = 2.e+20f ;
		temp:_FillValue = 2.e+20f ;
		temp:valid_min = -20.9f ;
		temp:valid_max = 19.5f ;

// global attributes:
		:history = "Mon May 24 11:34:35 BST 2010 - XCONV V1.90 11-May-2004" ;
}

In what respect is this netcdf file non-CF conforming and how can I fix it?

Greetings from sunny Holland,

	Geert Jan van Oldenborgh

--
Geert Jan van Oldenborgh
Global Climate Research
KNMI
oldenborgh at knmi.nl
www.knmi.nl/~oldenbor