I converted a Validated XHTML file to epub using Calibre. When Validating using the web site
http://validator.idpf.org/application/validate - the following problem was returned:type/ WARNING file/ The Fourteenth Day Play_split_000.html line/ -1 position/ -1 message/ Filename contains spaces. Consider changing filename such that URI escaping is not necessary! - I get about 47 of these, one for each page break/chapter. I have no idea what this means or how to fix it. Can Anyone help?