Reducing z axis range causes vectors to draw outside of cube.

I support 3D vector (u,v,w components) and volume visualizations from scientific data sets. I also allow users to change the range of the axes to reduce the density of the data plotted. This works fine for changes to the x and y axes but fails for changes to the z axis. Well it doesn't exactly fail--the z axis range is reduced correctly but the vectors and area of volume that should be clipped by the new axis range are still drawn *outside* the axes cube. To set the range of an axis I do (for example):

zMap.setRange(min, max);
zRangeMap.setRange(min, max);

Where zMap and zRangeMap are Scaler maps:

zMap = new ScalarMap(Z, Display.ZAxis);
zRangeMap = new ScalarMap(Z, Display.SelectRange);

As I said, the above code works for the x and y axes--data outside the axis range are clipped from the 3D display. However, data outside the z axis range are NOT clipped from the display.

Perplexed in Seattle,

JO