The error message is harmless. It's not very good style but you can ignore it. I need to recompile ProFTPD in a way it will still work on "normal" Linux distribution and on RedHat 9. And to fit this all is not easy. I hope I will fix it in the upcoming 1.0 release of LAMPP.
Autostart of webmin is also not easy. Okay, it's not a big problem. But it's to difficult to explain it here without having direct access to your computer (knowing the configuration of your system etc.)
LAMPP 1.0 will also start webmin automatically (if installed and wanted). I already programmed this and it works on my development system. So please wait some days... but I'm not sure when I'm able to release the new version.