This page (the parent) contains an <iframe> (the child). The <iframe> uses jQuery to find relevant <script>'s and stylesheet <link>'s sourced in the <head> of the parent, and attempts to add those resources to the <head> of itself. In other words, <script>'s and <link>'s found in the parent are dynamically added to the child using jQuery.
Things work fine as expected in IE8+, FF3+, Chrome and Safari -- in these cases, I see that the <script>'s and CSS related <link>'s are correctly found, cloned and appended to the <head> of the child <iframe>. In IE6 and IE7, the same code fails to properly clone() and append() any associated <link>'s from the parent into the child. Note that <script>'s work fine, but IE6 and IE7 reports an "illegal argument" error inside of jQuery when cloning and appending a <link>.
I would expect to see all scripts and styles in the parent, cloned and appended to the <head> of the <iframe> in IE6 and IE7. I certainly understand that an error inside of jQuery does not necessarily mean a bug in jQuery. However, the same code seems to work elsewhere, and jQuery claims support for IE6+ so I assumed I shouldn't see an error.
I only tried with 1.6.1, the latest as of June 3rd, 2011.
I know you'd probably prefer JSFiddle, but I tried to reproduce this bug in their enviornment and couldn't get things to fit together correctly so I gave up.