[jQuery] ie7 document not ready for namespace addition

[chrismarx]

id like to run this code

        if ( this.vml_capable ) {
                document.namespaces.add("v","urn:schemas-microsoft-com:vml");
                document.createStyleSheet().addRule("v\\:*",
"behavior:url(#default#VML); position:absolute" );
        ...etc

but i get an error even when running this within $(document).ready().
it does succeed if i use a timeout of a few seconds. is there some
element for which i could listen for the load/ready event that would
signal its ok to run this code?