Hi Maya,
I found out where your test solution and my solution differs, I use a DataPager and it's the pager that's causing this behviour.
I have a DataPager declared like this:
And the grid like this:
I also found a way no to use the CopyPropertiesFrom method and that is to switch order of the following lines:
So that I first instantiate the columnDescriptor and then setting e.Column to the new comboBoxColumn. like this:
I'm not sure this is considered a bug or not but at least I found the cause of the problem, and also a quite simple solution.
Btw it happens with other columntypes as well and I'm using the Office_Silver theme but I don't think that's relevant.
Tomas