Read-More link and the WYSIWYG editor

I have an input format and role for rich text editing using TinyMCE and the WYSIWYG module. When the rich text editing input format is used, the 'Read More' link does not appear inline. It appears on a new line aligned left. When the default html filter is used, the 'Read More' link appears properly inline.

I noticed that when the WYSIWYG input format is used, the 'Read More' link is wrapped in a DIV, but when the default html input format is used, the 'Read More' link is wrapped in a SPAN.

I have the input format configured with 'inline images', 'url filter', and 'video filter' enabled.

Can anyone offer suggestions as to how to get the 'Read More' link to appear inline regardless of whether a user is using the WYSIWYG editor? If that is indeed the problem? I have used similar configurations in the past that didn't have this issue.