Pls help me Mouse Move Issues

I am developing the flash game. I can’t able to get the correct Mouse Position in the Linux system.

Coding :
onMouseMove = function () {
trace(_root._xmouse)
trace(_root._ymouse)
}

PROBLEM: Some time Mouse move long Pixel , EX: x=750 and y=100. But i can able to trace x=710 and y=124 like that.
Pls help me how to solve the problem.

Note: But its working in WINDOWS system.

regards
sathishkumar