minor grid placements using our own function to draw minor ticks

Help! We've had to write our own minor grid capability to satisfy some user requirements. We've done this with just some calls to "line". Unfortunately, our data curve lines are being drawn behind our minor grid lines and when we zoom things are messed up. We can't draw our minor grids first because it messes up our legend. We've had some limited success using linkaxes when using axes to define our plot area, but all our plots begin with a call to subplot. Please point us in the right direction.