In IE (7) you can not really create a CBOE, because the save and cancel buttons disappear when you put the cursor in the WYSIWYG edit area.

Edit a collection and create or edit a CBOE (As in this collection: http://next.dev.curriki.org/xwiki/bin/view/GWT/Editor?xpage=plain&page=Coll_jmarks.Betacollectionx&mode=edit )

When you click to edit one of the CBOEs, then put the cursor in the edit ares, the title bar and save and cancel buttons disappear, and you can not actually save any content. This does not happen in FF.