Problem validating an <hr> tag

I have  page that was validating as XHTML 1.0 previously, so I added the
code snippet to include the validation icon.
Someone pointed out it's no longer validating, so I re-checked it and get
this error:

1.	Line 84
<http://validator.w3.org/check?uri=http%3A//www.sanjuan.edu/schools/campwint
hers/index.shtml#line-84> , column 26: the name and VI delimiter can be
omitted from an attribute specification only if SHORTTAG YES is specified 

	  <hr width="100%" noshade />

                            ^


I've looked for information regarding name and VI delimiter with regards to
the <hr> tag, and I'm not finding anything...
 
Any help?
 
(Also, why the change? I haven't touched the page, yet it no longer
validates when it previously did...)