It sounds as though your RBK file may be corrupt and it is looking for a non existent INS sound during the AUTOLOAD procedure when you turn on.
Are you using Ketrons default AUTOLOAD (from the 2011 update)?
If so its fairly simple to make a new RBK file by loading the two sounds from the 2011 update (thats if you even need them)and creating a new autoload, I cant do it right now but will try and look at it later.