[selectors] Attribute Selector Values Beginning with Digits

Hi,
   For the attribute value selectors, is it required that values 
beginning with digits must either be quoted or the first digit escaped? 
  For example:

p#test1[title=0] { color: green; }
p#test2[title="0"] { color: green; }
p#test3[title=\30] { color: green; }

<p id="test1" title="0">This line should be green.</p>
<p id="test2" title="0">This line should be green.</p>
<p id="test3" title="0">This line should be green.</p>

 From what I could find in the spec, it seemed to indicate that all 
three tests are correct, but Mozilla, Opera, Safari and OmniWeb seem to 
fail test 1 and pass tests 2 and 3, while the new IE7b2 and iCab pass 
all three.  If I understand correctly, that would make IE7 and iCab 
right and the others wrong.  Is that right?

-- 
Lachlan Hunt
http://lachy.id.au/