I have .pdf and .epub books on my device. I only put the first book the error log showed on the list and did not think to put one for .epub.
I live in the USA. My timezone is eastern standard. This message is going to be posted on Saturday, August 25, 2012 12:45pm (approximately.)
I opened Calibre and changed the tweak settings for publish date. No effect. I didn't think it would after reading your post. The date tweak settings seem more for altering how the user views information. Not how Calibre imports data.