Error in Validation Output Error

The validator is outputting this single odd error for every page I check. These pages were all error-free before today. This is the only error being output. I have a number of friends experiencing the same problem.

Typical problem URLs:

Validation Output: 1 Error
1.      [cid:image001.png@01CAE7A1.4EC98120] Line 1, Column 1: end of document in prolog
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
This error may appear when the validator receives an empty document. Please make sure

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

Received on Sunday, 2 May 2010 19:30:33 UTC