[GRASS-user] Several questions about vector maps

[Eric Gaba]

Good night.
As newbie I'm creating a map of the Falkland Islands using the NASA's SWBD shapefiles with GRASS 6.3RC6. After importing the ten tiles into GRASS in Lat/Lon, I merge them two by two using 'v.overlay' in order to have only one vector map. Isn't there a better way to merge several pieces of map in one big in one operation ? Should I use 'v.patch' ? When I try to use this last I've got an error message box 'couldn't execute "v.patch":invalid argument'. When I display this merged map, the sea areas are well displayed but I loose most of the lakes (the ones which weren't filled with any color in the separate tiles.
When I create a new project in UTM and re-project my map with 'v.proj', the module tells me that there are many (200) incorrect boundaries, as well as centroids outside area and areas without centroids, and when I display the map, several sea areas are white, showing me clearly that something didn't run fine. Can somebody tell me what is wrong ? Could it have something to do with the categories as I read in some threads ?

Thanks for your answers.
Eric
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