If you were using the ASP.NET menu control in vs2008, it would (at least for me) always render itself in front of any object. Once I updated to vs2010 and created an ASP.NET menu control, it kept "hiding" itself behind such objects as an embedded pdf. If you look at the source code that vs2008/vs2010 generates it is very different. Vs2008 (.net framework 2.0/3.5) creates tables when rendering a menu control on the client side. Vs2010 (.net framework 4.0) generates DIV/LI/UL statements by default on the client end. If you have tried raising the z-index to a very high level for the menu control in vs2010 and find that it is still rendered behind other objects, the following suggestion might work for you. When you define an ASP.NET menu control add the
RenderingMode property and set it to
Table:
<asp:Menu ID="mnuMain" runat="server" RenderingMode="Table"...
This will force the menu control to be rendered at the client side using tables and should render the menu control in front of any other control just like in vs2008! Hope this works for you as it worked for me.
Adiel