Toggling jumping ?

I get the feeling I'm using toggle in a way that it wasn't intended. This works:

      <div id="show" style='display:none;'>         <%= button_to_remote "Show", :complete => visual_effect( :toggle_appear, "show" ) + visual_effect( :toggle_appear, "edit" ) + visual_effect( :toggle_appear, "show_block" ) + visual_effect( :toggle_appear, "edit_block" ) %>       </div>

      <div id="edit">         <%= button_to_remote "Edit", :complete => visual_effect( :toggle_appear, "show" ) + visual_effect( :toggle_appear, "edit" ) + visual_effect( :toggle_appear, "show_block" ) + visual_effect( :toggle_appear, "edit_block" ) %>       </div>

<div id="show_block">   Show block </div> <div id="edit_block" style='display:none;'>   Edit block </div>

But the buttons "jump" on the page, as to the blocks. Any idea how to get one to just replace the other? I've tried setting delay to 0, e.g. visual_effect( :toggle_appear, "show_block", :delay => 0 ) without luck.

Many TIA, Craig