Hi Rob,
This seems to be a generic issue that I have seenin older versions across other sites - but as most environments opt for outlook as the main email source we have never spent much time investigating. I can recreate this on CRM 2011 RU 14 with IE 10 but the user setup is CRM 2011 ru12 with IE 9.
It Seems that when completing the body of an email the text can change throughout meaning that if a user clicks in different areas of the body it may not look very professional.
Thanks