Mosaic dataset has white space when zoomed in to certain levels

[DarrylKlassen1]

I have an image mosaic of ~150 TIF files and when I mosaic them it works fine.  But when I turn on the mask - 255, 255, 255 to show as no color, i get these strange white lines appearing.  This only appears when I am zoomed out, but as I zoom in it seems to disappear.  When I identify these spots, they are truly 255,255,255.  How do i get rid of these.  I have tried various tools, including, define overviews, build overviews, calculate statistics, and Define NoData.  None of these options seem to fix the drawing issue.  Any help is greatly appreciated.