Chapter Title breaking/splitting up in the TOC

Hello,
I am using FM11 on Windows 7.0.
When I update my TOC, one of the chapter titles break up and appear on 2 pages (as shown in image).
I have checked for Page breaks, extra spaces and Paragraph tabs etc.
Also, on pressing backspace the text gets shrinked (squeezed up) and not deleted.
When the chapter title is a single line, the page break dissapears. (I have another file where the chapter title is in 2 line and this works well there).
Help much needed!!
ASAP Please...

