Hi, infragistics developers!

This post is post continuation of: 

http://forums.infragistics.com/forums/t/43867.aspx

I managed to place UltraCombo in column header of UltraGrid, but it refuses to open...

What do I do not so?

This is simple application example:

How I can force to open this UltraCombo?

I have tried many variants, but solutions and have not found...

I will be grateful for any help!

Thanks!