I dislike those extra directories being created, so I turned it off.

for those with the source code,
In SettingsManager.jaya, find these lines:

try {
SetSaveDirectory(DEFAULT_SAVE_DIRECTORY);
} catch (IOException e) {
e.printStackTrace();
// this should not happen with the default directory
}

I commented them out, and no more extra incomplete and shared directories. No side effects for me, on winXP pro. Dunno what it might do on other OSs, but like I said, all it does in XP is stop those extra directories from appearing.