I'm new to GIS - more so in GRASS GIS. I installed GRASS GIS 6.4.3svn in my Windows 7 machine. No problem in installation.

• Downloaded SRTM-Geotiff file
• Location, Mapset all o.k
• Used r.in.gdal to import SRTM file
• Filled the sinks using r.terraflow
• Masked the filled raster
• Zoomed the required region & set the computational region
• Ran r.watershed using threshold=10000
• Got drainge, basin, stream & visual rasters
• Visual rendering of rasters (drainge, basin, stream & visual) - o.k
• Different Watersheds (basins) displayed for entire area
• Zoomed stream raster to find lat/lon of mouth of river (cross checked with Google earth)
• Converted the lat/lon as decimal
• Ran r.water.outlet using stream as input & gave the lat/lon as easting & northing
• Sadly the output display is blank
• Rerun r.water.outlet - only a small dot in the lat/lon point. No delineation of watershed for the given easting & northing
• All the above procedures as per manuals
• Self learning of GRASS GIS - no formal training

How do I get the watershed (basin) for the given lat/lon?