Can't be, TechRonin, at least as a usiversal thing, as I've expereinced it all the time and have not used a taskbar module in any theme yet, and I recycle all the time, always with several windows up. The easy solution is to use xLabel, but I've found it still has some quirks to work out, too (like some boxed labels not doing a onLeftClick action).
I think it may be a general windows config thing, because for me it will happen about 1/4 of every theme load for any theme using LsBox, while some people have never seen it.