Fixed element "jitters" when the page scrolls

Question

I've looked into this problem, found that it is Bug 201307 in firefox.

I also know that the "fix" is to apply overflow:auto; to the fixed box.

My issue is that I can't use that fix! I have a child element absolutly positioned outside of the fixed element. Is there another solution to this problem?

I can't show the example, but the code would look something like this:

<div id="nav">
  <div id="wrapper">
    <div id="float">
      <p>foo</p>
    </div>
  </div>

#nav {position:fixed;height:30px;}
#wrapper {position:relative;}
#float {position:absolute;top:30px;}

Any ideas?