[thredds] Odd black tile in TDS/WMS/Godiva2

TDS WMS folks,
[I asked this on the ncWMS list, but though it would be wise to ask
here as well]

Have any of you seen this strange "black tile" behaviour in TDS/ncWMS/Godiva2?
I'm using the WMS on TDS 4.2.5, and clicking the "Godiva2" link on the
bottom of the page.

When I look at some Fukushima forecast sea-surface temperature fields
from 
<http://geoport.whoi.edu/thredds/godiva2/godiva2.html?server=http://geoport.whoi.edu/thredds/wms/ncom_relo/fukushima#>
I see a black tile in the bottom right of my window for "water_temp"
and other variables (except for sea_water_velocity, which is odd,
since the eastward and northward velocity both have the black tile).

In case you don't want to fire up your browser, here's what it looks like:
http://coast-enviro.er.usgs.gov/models/share/2011-04-06_0834.png

Yet if I ask the WMS for a water_temp image over the same region for
the same time, it looks fine:
http://coast-enviro.er.usgs.gov/models/share/2011-04-06_0849.png

If I click right click on the black tile in Godiva2 and copy "image
location" I get
<http://geoport.whoi.edu/thredds/wms/ncom_relo/fukushima?LAYERS=water_temp&ELEVATION=0&TIME=2011-04-06T00%3A00%3A00.000Z&TRANSPARENT=true&STYLES=boxfill%2Frainbow&CRS=EPSG%3A4326&COLORSCALERANGE=2%2C21&NUMCOLORBANDS=64&LOGSCALE=false&SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&EXCEPTIONS=XML&FORMAT=image%2Fpng&BBOX=142.23782226564,32.757265625006,146.07398681642,36.593430175788&WIDTH=256&HEIGHT=256>
which indeed returns black.

If I copy the "image location" on a tile that works, I get
<http://geoport.whoi.edu/thredds/wms/ncom_relo/fukushima?LAYERS=water_temp&ELEVATION=0&TIME=2011-04-06T00%3A00%3A00.000Z&TRANSPARENT=true&STYLES=boxfill%2Frainbow&CRS=EPSG%3A4326&COLORSCALERANGE=2%2C21&NUMCOLORBANDS=64&LOGSCALE=false&SERVICE=WMS&VERSION=1.3.0&REQUEST=GetMap&EXCEPTIONS=XML&FORMAT=image%2Fpng&BBOX=142.23782226564,36.593430175788,146.07398681642,40.429594726569&WIDTH=256&HEIGHT=256>
which works fine.

I really can't see any difference between these except for the bounds.

I'm mystified.

Help?

Thanks
-Rich



-- 
Dr. Richard P. Signell   (508) 457-2229
USGS, 384 Woods Hole Rd.
Woods Hole, MA 02543-1598