The Author field controls how the name is displayed, and the Author Sort field controls how it's sorted. If both fields are "Dean Koontz", then the book will fall alphabetically under "D". if the Author sort is "Koontz, Dean", then it will sort under "K".
In my experience, simply changing the values in Calibre doesn't fix the file's metadata, it only fixes Calibre's database. In order to fix metadata on the file, I've had to convert it (you can convert it to the same format that you started from). For my Sonys, I've edited the device interface plugin in Calibre to feed the Author Sort field to the reader's database, but there's not an equivalent tweak for Kindle.
Last edited by trekchick; 12-07-2010 at 08:39 AM.