Page shifts when Spry Panel opens & closes

I'm having a problem with my page shifting to the left when I open the Spry Collapsible Panel links that I set up. I have a lot of content in the Panel Content divs with the overflow set to "auto". I understand that the text will shift left when the scroll bars are activated but I'm not sure why the page shifts when the panels are opening.

Any help would be greatly appreciated.

Here's the link to the page:
april10_test2/

Here's the SpryCollapsiblePanel.css:
@charset "UTF-8";

/* SpryCollapsiblePanel.css - version 0.5 - Spry Pre-Release 1.6.1 */

/* Copyright (c) 2006. Adobe Systems Incorporated. All rights reserved. */

/* This is the selector for the main CollapsiblePanel container. For our
* default style, the CollapsiblePanel is responsible for drawing the borders
* around the widget.
*
* If you want to constrain the width of the CollapsiblePanel widget, set a width on
* the CollapsiblePanel container. By default, our CollapsiblePanel expands horizontally to fill
* up available space.
*
* The name of the class ("CollapsiblePanel") used in this selector is not necessary
* to make the widget function. You can use any class name you want to style the
* CollapsiblePanel container.
*/
.CollapsiblePanel {
margin: 0px;
padding: 0px;
}

/* This is the selector for the CollapsiblePanelTab. This container houses
* the title for the panel. This is also the container that the user clicks
* on to open or close the panel.
*
* The name of the class ("CollapsiblePanelTab") used in this selector is not necessary
* to make the widget function. You can use any class name you want to style an
* CollapsiblePanel panel tab container.
*/
.CollapsiblePanelTab {
font: bold 0.7em sans-serif;
background-color: #FFFFFF;
margin: 0px;
padding: 0px;
cursor: pointer;
-moz-user-select: none;
-khtml-user-select: none;
}

/* This is the selector for a CollapsiblePanel's Content area. It's important to note that
* you should never put any padding on the content area element if you plan to
* use the CollapsiblePanel's open/close animations. Placing a non-zero padding on the content
* element can cause the CollapsiblePanel to abruptly grow in height while the panels animate.
*
* The name of the class ("CollapsiblePanelContent") used in this selector is not necessary
* to make the widget function. You can use any class name you want to style a
* CollapsiblePanel content container.
*/
.CollapsiblePanelContent {
margin: 0px;
padding: 5px 30px 20px 20px;
font-family: Georgia, "Times New Roman", Times, serif;
font-size: 14px;
line-height: 18px;
overflow: auto;
background-color: #FFFFFF;
height: 250px;
text-align: center;
}

/* An anchor tag can be used inside of a CollapsiblePanelTab so that the
* keyboard focus ring appears *inside* the tab instead of around the tab.
* This is an example of how to make the text within the anchor tag look
* like non-anchor (normal) text.
*/
.CollapsiblePanelTab a {
color: black;
text-decoration: none;
}

/* This is an example of how to change the appearance of the panel tab that is
* currently open. The class "CollapsiblePanelOpen" is programatically added and removed
* from panels as the user clicks on the tabs within the CollapsiblePanel.
*/
.CollapsiblePanelOpen .CollapsiblePanelTab {
background-color: #FFFFFF;
}

/* This is an example of how to change the appearance of the panel tab when the
* CollapsiblePanel is closed. The "CollapsiblePanelClosed" class is programatically added and removed
* whenever the CollapsiblePanel is closed.
*/

.CollapsiblePanelClosed .CollapsiblePanelTab {
/* background-color: #EFEFEF */
}

/* This is an example of how to change the appearance of the panel tab as the
* mouse hovers over it. The class "CollapsiblePanelTabHover" is programatically added
* and removed from panel tab containers as the mouse enters and exits the tab container.
*/
.CollapsiblePanelTabHover, .CollapsiblePanelOpen .CollapsiblePanelTabHover {
background-color: #FFFFFF;
}

/* This is an example of how to change the appearance of all the panel tabs when the
* CollapsiblePanel has focus. The "CollapsiblePanelFocused" class is programatically added and removed
* whenever the CollapsiblePanel gains or loses keyboard focus.
*/
.CollapsiblePanelFocused .CollapsiblePanelTab {
background-color: #FFFFFF;
}