Miscellanies of $K^0-{\bar{K}}^0$ mixing and $B_K$

We have computed $B_K$, using two different methods with staggered fermions on a ${16}^3\times 40$ lattice at $\beta =5.7$ with two dynamical flavors of a mass 0.01. % Using an improved wall source method, we have studied a series of non-degenerate quark antiquark pairs and observed no effect on $B_K$, although effects were seen on the individual terms making up $B_K$.