Validation error?

I am getting the following error when I try to validate one of my files (XHTML 1.0)
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Line 37, column 17: 
  <map name="admap">
                   ^
Error: required attribute "id" not specified 
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This is the only error reported. I have looked through the specs and DTD and can 
find no indication that the id attribute is in fact required. Can someone correct or 
confirm this?