That's why I am saying I have a bug. I should get the result as you posted, but I in your case would get:
Colleen McCullough,"epub, mobi, zip","Caesar"
For this entry it is ok, since only one author, but if two authors - they will get separated.
There are no settings for csv catalog what I know of, so I didn't mess it up. I don't get an error message. I just get wrong csv file. My calibre is up to date.
Microsoft office 2007.
I'd really like to fix this somehow