I have a EUSSO Technologies SOHO KVM Switch which connected to a (X)ubuntu and a FreeBSD boxes. After switching between them, the mouse was hooked up at the X Window of (X)ubuntu. I tried many methods that searched from the net but in vain.
Fortunately, I discovered that “Scroll Lock” + “Scroll Lock” + “m” can reset the mouse after switching between the 2 boxes.
My problem is solved, happy :-)