So I had a function:

function fv_loadUrl( parms )
{
var elem = parms.elem;
var href = parms.href;
window.location.href = href;
return true;
}

Works like a champ in FireFox, but not in MSIE 6. I read a post that speculated the script was terminating before the page could load. Changing the return true; to return false; solved the problem.