Cover Art issues in Calibre 0.6.52
I'm having issues with editing metadata in ePubs in the most recent version of Calibre - I've looked through the forum and haven't been able to find an answer.
I downloaded some drm-less ePubs, and have also converted some other formats to ePub through Calibre for my new Kobo and it seems the file does not want to retain the changes to the metadata I make.
Some of the files have incorrect cover art and titles, so in Calibre, I would edit the metadata and insert the right cover picture - it appears to be correct looking at it in Calibre, as well as when I open the book's folder in Windows Explorer, but when I load it onto my Kobo, it still shows the old metadata and wrong cover. I've tried changing the metadata both before and after converting and neither method seems to be working.
I would appreciate any help you can offer, perhaps I'm doing something wrong?