Need help: Scrollbar issues in Safari

I've got a site with css scrollbars that works in FF and IE but not in Safari. The scrollbars appear but they don't scroll. I'm using the same code on other pages that work, but they are scrolling a block of text and not a block of images (in a table).

Here's the style:

.PageContentDiagram {
margin-right: 40px;
margin-left: 40px;
height: 370px;
overflow: auto;
overflow-y: auto;
overflow-x: hidden;
scrollbar-track-color: #FFFFFF;
scrollbar-arrow-color: #96BA74;
scrollbar-face-color: #CCDDBD;
scrollbar-3dlight-color: #CCDDBD;
scrollbar-shadow-color: #FFFFFF;
scrollbar-highlight-color: #FFFFFF;
scrollbar-darkshadow-color: #CCDDBD;
}

and the snippet from the page:

<div class="PageContentDiagram">
<div class="imgDiagram">
<table width="530" border="0" cellspacing="0" cellpadding="0">
<tr valign="top">
<td class="txtPage" style="padding-right:10px;">Park Media’s Context Delivery Platform can be configured a myriad of ways unlimited by media type or content strategy.</td>
<td class="txtPage" style="padding-left: 10px;">The Platform’s flexibility meets different location-specific content and scheduling needs in this illustration.</td>
</tr>
<tr>
<td><img src="images/PM_NetworkDiagram_01.gif" width="265" height="180"></td>
<td><img src="images/PM_NetworkDiagram_02.gif" width="265" height="180"></td>
</tr>
<tr>
<td><img src="images/PM_NetworkDiagram_03.gif" width="265" height="181"></td>
<td><img src="images/PM_NetworkDiagram_04.gif" width="265" height="181"></td>
</tr>
<tr>
<td><img src="images/PM_NetworkDiagram_05.gif" width="265" height="182"></td>
<td><img src="images/PM_NetworkDiagram_06.gif" width="265" height="182"></td>
</tr>
</table>
</div>
</div>

See it live here: http://www.mckenziefrancis.com/Markansas/parkmedia/network_diagram.htm

I appreciate any suggestions.