The attribute filter does not work with a label element in IE 7 (jQuery 1.3 Beta 2).

The following works in FF 3, but not in IE 7:

$('label[for=username]');

But this works in IE 7:

$('label[lang=en]');

The HTML source:

<form method="post" action="">

<fieldset>

<label for="username" lang="en">Username</label>

<input id="username" type="text" name="username" value="" />

</fieldset>

</form>

This was also the case with the jQuery 1.3 Beta 1. But it worked with jQuery 1.2.6.