AJAX extensions UpdatePanel slow for button_click

[snazzy]

I have a update panel with another panel inside to show for entering
information. A button within the panel calls for a gridview to show outside
the panel. When I select to close the panel after the gridview has displayed,
the button to close is extremely slow. The process to close is simply to
make the panel visible set to false. Gridview is shown using asyncpostback
and have tried the same for the button close when click with no improvement.
Update panel is set to always and viewstate is true for all fields. I have
tried change update panel to conditionals and viewstaet to false with no
improvement.