This is probably caused by symbolic preferences on your machines. I guess you have defined x as a symbolic variable before this code.
By default, in the case of symbolic variables, MATLAB does not convert to a floating-point value; therefore, sin(2) is the default answer. If you are getting a value of 0.9093, then that means that somehow the preference has been changed by running
If you want always to get floating-point output, run the above line on all machines. To get the default preferences, run