grid not displaying when updated in asp.net updatePanel

I have a grid which on first load is displayed correctly in an updatePanel. However on a postback event the grid disapears! When I check the source code all appears fine. The updatePanel updatemode="always" nowhere on the page is visible="false". When I step through the debbuging everything is created correctly, it just isn't displayed

If i remove the updatepanel the grid displays correctly, does anyone have any ideas why this would happen?

Maybe this is because the script in update panel is not executed after partial postback?