Hitting return twice at the end of a heading doesn't go out of the heading in IE

• XE 1.8.1 + IE6 / IE7
• Create a new page in XWiki syntax 2.0
• Input "Title 1" on the first line. With the caret at the end of the line, click on "Title 1"
• Hit return twice. Input "Title 2" on the second line and then, with the caret at the end of the line, click on "Title 2".
• User needs to hit return 3 times to go out of the heading to the next line
• Input "Title 3" on the next line and make it a title 3
• User needs to hit return 5 times to get out of the heading
• Same thing when inputting a Title 4 on the next line

The editor does not behave as it does in FF3.