When the tracking feature is enabled some of the existing features don't work properly. For eg:
a. If existing text were bulleted they were not displayed properly.
b. If bulleted content was copied over from a web page and pasted into the RadEditor control formatting was not retained.
c. If text in the editor that was modified previously and not accepted by a user, a change made to the same text after some time does not capture the new username and date time stamp by the same /different user. 

Please fix the tracking feature for SharePoint