Could well be...

I haven't looked at the package yet so I don't know how the init file looks, but if it's a script check
if it tries to start displayserver from the location you mentioned (any error messages on boot?)
If it's a script and does that, try changing the path. If it isn't a script you could try creating a
symlink /usr/local/bin/displayserver -> /usr/local/displayserver/displayserver

/Michael