Any page moderated by mollom (like the ones where users can post comments) now fails to validate as XHTML 1.0 strict. The reason for this is the autocomplete attribute which is served to many non-human useragents including the w3c validator that uses the referer: http://validator.w3.org/check/referer
I know that this attribute is part of a spam trap and plays an important role there, but if something else is possible, can you look into alternatives to this non-standard attribute? https://wiki.mozilla.org/The_autocomplete_attribute_and_web_documents_us...
It's a shame that this is the only validation error on many mollom-using Drupal sites so when you have time, I'd be really happy if you could revise the spam trap or allow one to add "trusted sites" that don't get served the spam trap.