Iframe over applet flickering

I am using a iFrame to show content over my Applet in my online game.

It work's perfectly in Safari, Chrome, Firefox, Opera etc. But as always not in Internet Explorer on Windows.

When the iframe opens over the applet, the content become to "Flickering"/"Blinking" like the applet is updating a lot, which it doesn't.

What can i do? I am using this:

<applet id="applet" code="main.AvatarClient.class" archive="qqqqqAvatarClient.jar" name="Chat" width="760" height="582" scriptable="true" MAYSCRIPT="true" >
   <param name="cache_option" value="YES" / >
   <param name="localization" value="locDK/" />
   <param name="userName" value="<?=$user?>" />
   <param name="password" value="<?=$pass?>" />

And the overlay where iframe is:

 <div class="add-block qw no-rounded-borders" id="wo" style="position:absolute;left:756px;margin-top:-30px;z-index:99999999999999999999999999999999999999999999999999999999999999;height:380px;width:495px;display:none;">   
            <iframe id="my" src="loading.php" frameborder="0" height="380" width="496" scrolling="no" style="z-index:9999999999999999999999999999999999;position:absolute"></iframe>
 </div>