Just trying out Repetier Server on Windows for the first time, and I was migrating over my custom G-Codes that I use to turn on the E3D hot end fan, and an LED lamp at print start. I noticed that the commands did not work when sent from the server, but did work when sent from host. Changed all to upper-case characters, and then it worked.
Would be nice to Auto-Upcase if this is standard behavior, and not a bug.