Hello , I am owner of Yamaha Montage White 6. I bought it in Greece from Nakas Music Store a year ago. I have issues after loading my backup file that created in a common montage (not white edition).  I noticed the following difference about mine and other common montages. All performances that have user samples , are sounds quite lower in volume (only elements that use user samples). After using the same backup file in many backline Yamaha montage keyboard I noticed that only in my own keyboard has these issues . And I noticed this weird thing . 

My OS version is 3.52.00 and in Yamaha ’s site the latest OS version for Yamaha montage is 3.51.00. What is exactly happened ?

Thank you in advanced !