The eclipse code formatter adds a trailing space in each empty Javadoc comment line (see screenshot).
I've also had this issue and solved it by doing a Search/Replace in Eclipse.
^([\s]+\*)([\s]+)$
into the Containing text field.What this is doing is searching for lines that start with blank space characters that contain a * and then further blank space and no other content. It then replaces the whole line with the first matched part of the regex, which is just the initial spacing and * of the comment line.