Ignored z-index with IFrame. Drop down menu hidden. - asp.net

Question

In Internet Explorer only (Works fine in Chrome and Firefox), it always puts a PDF displayed in an iFrame over top of any other objects on the page. I have a horizontal menu above that has drop down menus that become hidden behind.
I have tried forcing the site in IE9 mode, z-index on all items and parent items, adding wmode = to transparent or opaque.
This only happens when a pdf is loaded in the iframe. If a webpage is loaded, the menu appears over top as it should.
CSS:
iframe
{
position: relative;
z-index: 0;
}
#Standings_Container
{
float:left;
text-align: center;
width: 100%;
z-index: 0;
position: relative;
}
#nav .Menu_Child {
display:none;
position:absolute;
left:0;
top:26px;
height:auto;
float:left;
width:174px;
overflow:hidden;
z-index: 10000;
}
HTML:
<div class="Menu_Child">
<ul>
<li>Applications</li>
<hr class="Menu_Child_HR" />
<li>Schedules</li>
<hr class="Menu_Child_HR" />
<li>Standings</li>
<hr class="Menu_Child_HR" />
<li>Rules</li>
<hr class="Menu_Child_HR" />
<li>Sponsors</li>
<hr class="Menu_Child_HR" />
<li>Gym/Field Directions</li>
<hr class="Menu_Child_HR" />
<li>Register Online</li>
</ul>
</div>
<div id="Standings_Container">
<iframe style="margin-top:8px;" scrolling="yes" width="850" height="600" src="[PDF URL]"></iframe>
</div>

Answer 1

I have come across this so many times, and unfortunately, it seems to be a limitation of the way IE (specifically the Adobe Windows PDF plug-in) renders the PDF. It basically generated it last, over every other element on the page.
Whereas Flash embedded objects could overcome this using the wmode="transparent", this is not the same with the PDF plugin. I will try to play around with the windowless or windowed parameter, but I am certain I already tried this.
Unfortunately for myself, and others, shifting the PDF lower and/or widening the gap below the navigation is not an option.
Seems to me, but I could be wrong, that Adobe need to revisit the way IE handles PDF or Microsoft to use a different rendering engine.
fabio

Answer 2

After a week of trying different solutions and fixes, i couldnt find anything that would work for my specific situation. Instead i just made the vertical spacing on my sub menus much shorter and pushed the pdf in the iframe further down on the page so the drop down menus never overlap.