rounded corner extender not working consistantly

<formid="form1"runat="server">

<asp:PanelID="PanelTop"runat="server"BackColor="AliceBlue"Height="50px"Width="800px">

<strong><spanstyle="font-size: 16pt; color: #1e90ff">KSM Information Systems --

PC Inventory <br/>

<tablewidth="800">

<tr>

<tdstyle="width: 831px; height: 18px; text-align: center;"valign="top">

<spanstyle="font-size: 16pt; color: dodgerblue">

<asp:ButtonID="Button2"runat="server"BackColor="#507CD1"Font-Bold="True"ForeColor="White"

PostBackUrl="~/AddMultiplePCs2.aspx"Text="Enter New PC's"/></span></td>

</tr>

</table>

<br/>

</span></strong>

</asp:Panel>

<br/>

<asp:PanelID="PanelMain"runat="server"BackColor="AliceBlue"Height="12px"Width="797px">

te

<asp:ButtonID="BtnViewALLpcs"runat="server"BackColor="#507CD1"Font-Bold="True"

ForeColor="White"PostBackUrl="~/ViewAllPcs2.aspx"Text="View All PC's"BorderStyle="None"/>st<br/>

<br/>

</asp:Panel>

<br/>

<asp:PanelID="PanelMain2"runat="server"Height="50px"Width="796px"BackColor="AliceBlue">

<strong><spanstyle="font-size: 16pt; color: #1e90ff">KSM Information Systems --

PC Inventory <br/><tablewidth="800">

<tr>

<tdstyle="width: 831px; height: 18px; text-align: center;"valign="top">

<spanstyle="font-size: 16pt; color: dodgerblue">

<asp:ButtonID="Button3"runat="server"BackColor="#507CD1"Font-Bold="True"ForeColor="White"

PostBackUrl="~/AddMultiplePCs2.aspx"Text="Enter New PC's"/></span></td>

</tr>

</table><asp:ButtonID="Button1"runat="server"BackColor="#507CD1"Font-Bold="True"ForeColor="White"

PostBackUrl="~/Checkout2.aspx"Text="Checkout a PC"/></asp:Panel>

<br/>

<br/>

<br/>

<br/>

<br/>

<asp:contentplaceholderid="ContentPlaceHolder1"runat="server">

</asp:contentplaceholder>

<divstyle="font-family: 'Arial Unicode MS'; font-size: 12pt;">

<asp:ScriptManagerID="ScriptManager1"runat="server"/>

</div>

<cc1:roundedcornersextenderid="RoundedCornersExtender1"runat="server"corners="Bottom"

targetcontrolid="PanelTop"BorderColor="224, 224, 224"Radius="10"></cc1:roundedcornersextender>

<cc1:DropShadowExtenderID="DropShadowExtender1"runat="server"Radius="10"TargetControlID="BtnViewALLpcs"Opacity="6"Rounded="True">

</cc1:DropShadowExtender>

<cc1:roundedcornersextenderID="RoundedCornersExtender2"runat="server"BorderColor="224, 224, 224"Radius="10"TargetControlID="PanelMain"Corners="Bottom">

</cc1:roundedcornersextender>

<cc1:roundedcornersextenderID="RoundedCornersExtender3"runat="server"BorderColor="224, 224, 224"

Corners="Bottom"Radius="10"TargetControlID="PanelMain2">

</cc1:roundedcornersextender>

</form>

Please provide more details...What is the inconsistent behavior?