Niels, Sounds like you have validate_doc_update function defined in one of that database's design documents. Basically, you'll want to ensure that this function doesn't check for the "url" property when the document's "_deleted" property is true.
Here's an old thread for a simliar problem: http://mail-archives.apache.org/mod_mbox/couchdb-user/201001.mbox/%[email protected]%3E Cheers, Zach
