I have page that has several tabs (horiz state nav control) across the top that toggles one gridview on/off for each tab. When I view it interactively the columns don't size correctly when switching tabs to view each grid. I have styles applied to each column to specify width, and its set to force width. The only one that sizes correctly is the gridview that is shown initially. I can tell you which project/page if you want to see it in action.