Look at my previous post you also need to edit the html, not just the image.
ePubFixer - http://code.google.com/p/epubfixer/
Edit your TOC, by Adding, Renaming, Shifting Chapter, Change chapters order or nest chapter into Part or Book easily by Drag and Drop. Split files by Chapters & Auto Detect phrase for your chapter heading. Also edit the reading order, fix margins & Edit your file with Sigil and restoring your previous TOC that was lost. Edit your cover without reconverting the file, Create an Inline TOC