I use hydrogen Drum Machine 0.9.6-svn- and Ubuntu 12.04.1 LTS
I wanted to install the GSCW kit... I downloaded the zip files, but I had a few problems with the next steps...
When I used the librairy import tool with the GSCW kit (local file etc), I got the new drumkit available in the bottom right window, and I was able to load it in the pattern editor with all the instrument names, but I had no sound at all (in both windows) !! Actually, in each instrument, the "layers" were empty (no file loaded).
I checked the directory .hydrogen/data/drumkits/GSCW-1 (and 2...). In it, I had several sub-directories (kick, snare, etc), a drumkit.xml file, and a licence.txt file. In each sub-directories, there were several .wav files. Everything seemed to be all right.
I checked the other sound librairy directories (the other drumkits, .hydrogen/data/drumkits/xxx), they had the same design. The only difference I noticed was that in the other drum directories, there were no sub-directories, all the sound files were in the main drum directory, along with the licence and drumkit.xml. files.
I opened the drumkit.xml file for the GSCW kit and checked the sound file names. All the files names, including the subdirectories, were correct. I thought maybe hydrogen is not able to load an instrument librairy containing subdirectories...? So I moved all the files from the subdirectories into the main directory (.hydrogen/data/drumkits/GSCW-1), erased the subdirectories and edited the drumkit.xml file manually to update all the file names.
I opened hydrogen and... I had access to all the sounds of the GSCW-1 drumkit ! :)
So it seems that hydrogen cannot deal with sound librairy including sub-directories or... well, any idea ?