public void OnRibbonLoad(IRibbonUI ribbon) did not get executed

[B W]

I am adding checkbox on Excel ribbon.

I have taken example from Excel-DNA group and added codes in the project.

It is my understanding that the codes need to execute ribbon (IRibbonUI).invalidate() to get the state reflected on the checkbox itself and other checkboxes.  To do that, the code need a handle on ribbon. and the ribbon is held somewhere by OnRibbonLoad.

However, OnRibbonLoad did not get executed, thus ribbon being null.

Is there other method to get hold of ribbon?

My Excel-DNA is old, ExcelDna.Integration.0.34.6\lib

Thank  you

Bing