I’m pretty sure each custom field requires it’s own unique key.
You can have multiple values for the same key as long as they are entered separately as individual custom fields.
Example:
key=”currently_reading”, value=”harry potter”
key=”currently_reading”, value=”lemony snicket”
Could you be more specific when you say “messes up all links”? Can you post a link to your site so we can see how they are messed up? Also, when you say you “edit them out” are you referring to the links in your post, or the custom fields? Are you entering the links using the Visual editor or the Code editor? A little more info will help people to help you…
http://sidestreammedia.net/minimal-perfection/minimal-perfection-24-im-gonna-go-smash-my-head-into-the-wall-a-few-times/ Is one of the messed up posts while http://minimalperfection.com/post/minimal-perfection-24-im-gonna-go-smash-my-head-into-the-wall-a-few-times is what all the links looked like. I did try to edit the links out both with the WYSIWYG and the HTML editor along with trying to remove the custom fields and it still won’t go back. It’s 2 custom field entries both with the key of author and 2 different values.