[GRASS-user] problem with reprojection of Hydro1k data

[FAROUX STEPHANIE]

Hello,
First i'd like to know if anybody already used the Hydro1k data from USGS?
I try to make global maps of parameters from continental ones.
The initial projection is lambert azimutal equal area, with different 
latitude and longitude of origins for different continents. I defined 
one location by continent; then i reprojected all maps in a latlon 
global location, with WGS84 datum.
There are gaps between continents, for example between Asia and Europe 
and between Europe and Africa.
I wonder if the problem comes:
- from the data which don't perfectly cover the earth
- from my reprojection in grass
Thank you if somebody can help me
Regards
Stéphanie