In there files must be a lines with path to prx files.
vhs.txt - to plugins, that worked in vhs
game.txt - to plugins in psp games
game150.txt - to plugins in home-brew's
pops.txt - to plugins in PSX games.
Alsow i recomend delete config file into 'seplugins'.
its vsh.txt and its for plugins that workes in the vsh/xmb :P