I'm having absolutely no luck getting my epub to validate with what should only be a date error. Here's what I've done based on my limited training via Anne-Marie's lynda.com video on ID4 to EPUB et al.
Here's what I'm doing: I create the EPUB first. I open the .EPUB file in Springy; then I edit the content.opf file in TextWrangler (<dc:date>2011<dc:date/>). I save the file in TextWrangle then close Springy (simply via red close button). Also, I have turned off the “preserve mac setting.” I try the validator again and I either get the same date error message, or I get the very extended error message where every file is wrong, not represented, etc.
I have also tried the method outlined in the video with the EPUB Zip 1.0.3 utilities: first unzipping the epub, changing date in textwrangler and zipping the folder back up (which gives me the prompt to replace the file). That's when I get the full list of errors in zip file vs opf file (screen shot attached).
I wasted many hours today and am no further. I just cannot figure out what I'm doing wrong.