If you don't mind, I'm going to quote your notes from that issue:
referencing: http://www.whatwg.org/specs/web-apps/current-work/#selector-disabled
<blockquote>
As for the DOM viewer :disabled test, I see failures with the following clients:
<ul>
<li>IE (all versions) erroneously fails to match o2 (option in a disabled group)</li>
<li>Safari&lt;6 erroneously matches o3 (option in a disabled select)</li>
<li>Safari 6.0  erroneously matches o3 (option in a disabled select) and fails to match g2d; o2 (disabled group; option in a disabled group)</li>
<li>Opera&lt;15 (Presto) erroneously matches o3; g4; o4 (option in a disabled select; group in a disabled select; option in a group in a disabled select)</li>
<li>Android (all versions) erroneously matches o3 (option in a disabled select)</li>
</ul>
</blockquote>
```
<select id=s1><option disabled id=o1d></select>
<select id=s2><optgroup disabled id=g2d><option id=o2></select>
<select id=s3d disabled><option id=o3></select>
<select id=s4d disabled><optgroup id=g4><option id=o4></select>
```