And if you're using a wireless mouse, think about replacing the batteries or changing your surface.
Of course, neither of these suggestions addresses the fact that your mouse works well in your OS...
Get rid of the USB mouse and get a PS2 mouse instead. Also Logitech mice tend to have more of these issues than Microsoft mice expecially with VIA drivers if any of those apply to you.
Is the mouse sticky in Vegas only during rendering? Hit ctrl-alt-delete to see the CPU utilization during different uses, it can also be the CPU hitting 100% (see which app uses the CPU during those times).
is the PS2 the purple input? I guess I forgor about using that cause ive has intellapoints for so long. anyone know that best place to get a PS2 that is considered "the best" one.