</A> flagged as illegal when previois "" missing

This is flagged with Error 'end tag for element "A" which is not open.'
  <p><A HREF=http://thomer.com/vi/vi.html><img src=vi.powered.gif 
ALT="vi"></A>

The following is accepted by the validator
<p><A HREF="http://thomer.com/vi/vi.html"><img src=vi.powered.gif 
ALT="vi"></A>

So I understand that the error is the absence of the "" around the url...

Gruss PB