W3C//DTD XHTML+ARIA 1.0//EN! DTD did not contain element declaration for document type name

Ladies/Gentlemen-

The Validator check of XHTML+ARIA 1.0 documents, while working properly from
0900 HRS Zulu through 1200 HRS Zulu on 4 Mar 2011, began, at approximately
1400 HRS Zulu, failing to recognize the DTD.  As such, on documents that it
once could validate, it NOW throws over 1,000 errors failing to recognize
attributes from xmlns to role, every single HTML attribute is no longer
recognized and throws an error.

The issue exists whether checking documents locally or via live server.

This is supposed to be the W3C and MIT?  

C. Thacker
CPRG Ltd
Springfield OH
USA

NOTE: Whenever possible, give the address of the document you were checking.