Hmm...The error message really does suggest that the problem is in the XML DOCTYPE declaration. But, I agree, there doesn't appear to be a problem with the top of your XML file - I plopped your snippet into an EAD and was able to run the cookbook transformation without errors. So, let's check a few things:
As suggested by Mark Carlson, try removing the line breaks in the DOCTYPE.
I imagine when you open the XML file (C2005.1-eadfindingaid.xml) in Oxygen, you don't get a squiggly red line under the "<!DOCTYPE ead" section?
The XML otherwise validates?
>>> Anna Kresmer <[log in to unmask]> 04/05/10 11:32 AM >>>
Thanks for responding. Unfortunately, I checked and there was already a
space in the DOCTYPE where you highlighted it. I messed around with it,
even adding an extra blank line and nothing has changed. Same error. Here
is what the top of my EAD file currently looks like:
<Xxml version="1.0" encoding="UTF-8" standalone="no"?>
<Xxml-stylesheet type="text/xsl" href="eadcbs5.xsl"?>
<!DOCTYPE ead PUBLIC "+//ISBN 1-931666-00-8//DTD ead.dtd (Encoded Archival
Description (EAD) Version 2002)//EN" "ead.dtd">
<eadheader langencoding="iso639-2b" audience="internal"
countryencoding="iso3166-1" dateencoding="iso8601" id="a0">
Maybe I have missed something?