The pagebar plugin does break om some code:
a) remove the nbsp; in the pagebar plugin code
b) remove the <!– 216 comments in the pagebar plugin code
… but this is not the main problem, the main problem is that it is auto inserted before the start of the xml code.
What exactly is the siteinfo.xml file. the pagebar should only appear after the WP events which were selcted in the options. I have not idea, why it is launched in your example. Is it a WP page? Please give some detail, maybe I can help… ?
Ah, was too early in the morning, you meant the google sitemaps generator.
http://www.arnebrachhold.de/projects/wordpress-plugins/google-xml-sitemaps-generator/
I’m gonna take a look……. soon!