Samer,
the first thing I tried at the store when seing the manual bass wasn't working was to go and check if the arabic mode was turned on or off. It didn't matter which way I selected it, the manual bass still didn't work. Finding the tap tempo and now the 1/2 measure fill function makes sense that it is not the arabic mode on and off but rather the oriental operating system which comes loaded into the X1 oriental keyboards. You know you have this operating system installed by watching the screen while the keyboard boots up and says "live oriental" at the start up.
George Kaye
Kaye's Music Scene