[idvusers] Viewing GeoTIFF images in IDV

I'm trying to use the ETOPO1 Global Relief Model colored image
http://www.ngdc.noaa.gov/mgg/global/global.html
and
ftp://ftp.ngdc.noaa.gov/mgg/global/relief/ETOPO1/image/
as a background for a netCDF grid time series.
I've not been able to figure out how to get IDV 2.7u2 to display these GeoTIFF images properly, however. In fact IDV seems to have problems reading any image in GeoTIFF format--or perhaps I just haven't figured out the right procedure. I can't seem to find any guidance on this in the user guide or previous forum posts.
What is the correct process to use when adding a GeoTIFF to a display?

Background info on GeoTIFFs: http://www.remotesensing.org/geotiff/faq.html

Thanks!
Wayt Gibbs
Intellectual Ventures
Bellevue, WA