Bug in the validator

See the page 
http://validator.w3.org/check?uri=http%3A%2F%2Fvalidator.w3.org%2Fdocs%2Fhelp.html&charset=%28detect+automatically%29&doctype=XHTML+1.0+Transitional&group=0

***
Failed validation, 6 Errors

Line 350, Column 15: XML Parsing Error: Entity 'mdash' not defined.
Line 523, Column 51: XML Parsing Error: Entity 'auml' not defined.
Line 571, Column > 80: XML Parsing Error: Entity 'nbsp' not defined.
Line 571, Column > 80: XML Parsing Error: Entity 'nbsp' not defined.
Line 596, Column > 80: XML Parsing Error: Entity 'copy' not defined.
Line 597, Column > 80: XML Parsing Error: Entity 'reg' not defined.
***

What is it?

Several hours ago my pages were valid, but now they are not valid because
validator says that character entities  , © and other are not 
defined.

Please check how validator does work...

Sincerelly,
Artemy Lomov
http://www.lomov.ru/ - the page is 'not valid XHTML' since today... 

Received on Wednesday, 25 July 2007 13:19:34 UTC