Try applying the following patch to libbonoboui (from CVS, or other versions will be suitable too), it solves your problem. The problem is, as you can see, in toolbar implementition of bonobo-ui-toolbar, which is differ from gtk toolbar. Now this work is almost senseless, because of new ui manager in gtk. There is need to port libbonoboui code to new action-based user interface scheme. But I don't know, is this work in process. I also don't know is now time to apply this code to CVS of bonoboui, because of code freeze before release 2.6. Maybe, we should fill bug in bugzilla?
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